Novel dizocilpine derivatives as peripheral nmda receptor antagonists

ABSTRACT

The present invention relates to compounds of formula (I):for use as peripheral NMDA receptor antagonists.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.16/308,654, filed Dec. 10, 2018, which is a 35 U.S.C. § 371 nationalstage patent application of International Application No.PCT/EP2017/064409, filed Jun. 13, 2017, which is based upon and claimsthe benefits of priority to European Application No. 16305712, filedJun. 13, 2016. The entire contents of all of the above applications areincorporated herein by reference.

The present invention relates to the identification of novel dizocilpinederivatives and to the use of such compounds as peripheral NMDA(N-Methyl-D-Aspartate) receptor antagonists in particular for thetreatment of pulmonary hypertension (PH), and preferably for thetreatment of pulmonary arterial hypertension (PAH).

Pulmonary hypertension defines a group of clinical conditions presentingwry circulation pressure. Thus, a normal mean pulmonary artery pressure(mPAP) at rest is 14±3.3 mm Hg, and a PH is commonly defined as anincrease of mPAP≥25 mm Hg at rest, as assessed by right heartcatheterization. The PH diseases are classified into five classes: class1 to class 5 (Management of pulmonary arterial hypertension. McLaughlinV. V., Shah S. J., Souza R., Humbert M., J. Am. Coll. Cardiol., 2015 May12; 65(18):1976-97). In particular, pulmonary hypertension diseasesinclude pulmonary arterial hypertension (group 1), such as pulmonaryveno-occlusive disease and/or pulmonary capillary hemangomatosis, PH dueto left heart disease (group 2), PH due to lung diseases and/or hypoxia(group 3), chronic thromboembolic pulmonary hypertension (group 4), andother PH conditions with unclear multifactorial mechanisms (group 5).

Among pulmonary hypertension diseases, the pulmonary arterialhypertension is a devastating pulmonary vascular disease causingbreathlessness, loss of exercise capacity and ultimately death. Asrecently, pointed by the inventors, this disease is characterized by achronic increase in pulmonary artery pressure (above 25 mmHg), caused byan important remodeling of small pulmonary vessels associated toinflammation, leading to progressive vessel occlusion, ultimatelyleading to right ventricular failure and death (Cohen-Kaminsky S et al.,Drug Discovery Today 2014, Huertas A, et al., Circulation, 2014).

There is unfortunately no cure of PAH. The current PAH therapies areessentially focused on decreasing pulmonary vascular resistance bystimulating pulmonary vasodilation (prostacyclin analogues,phosphodiesterase type 5 inhibitors, and endothelin receptorantagonists) (Humbert et al., N. Engl. J. Med. 2004, O'Callaghan D S, etal. Nat. Rev. Cardiol., 2014). These agents have some anti-remodelingproperties, but there is no current anti-remodeling strategy approvedfor PAH. In spite of these treatments targeting endothelial celldysfunction that are now available to improve quality of life andsurvival, in most patients the outcome is very poor. Median survival ofPAH (that was 2.8 years in the 1980's) remains inferior to 5 years andrefractory cases are candidates for heart-lung transplantation, a majorsurgery with current limitations due to shortage of organ donors andsevere long-term complications (5-year survival is only 50%). Somehemodynamic and clinical effects of the tyrosine kinase inhibitorimatinib have also been reported in severe PAH, but at the expense ofsevere side effects.

Therefore, the discovery of new treatments targeting other PAHpathomechanisms would be useful to slow, stop, or even reverse diseaseprogression.

In PAH, right heart failure is secondary to extensive remodeling andprogressive obstruction of small pulmonary vessels, a complex andmultifactorial process involving uncontrolled smooth muscle cellproliferation. Endothelial cell dysfunction is thought to mediatestructural changes in the pulmonary vasculature, yet it is increasinglyevident that inflammation plays a role in PAH pathogenesis (Price etal., Chest, 2012). It has been established that i) inflammationinfluences vascular remodeling and (ii) immune dysfunction andautoimmunity may contribute to the pathophysiology of PAH (Perros etal., Am. J. Respir. Crit. Care Med. 2012, Med. Sci. 2013, Am. J. Respir.Crit. Care Med., 2013).

Recently, the inventors of the present invention demonstrated that NMDAreceptors contributes to pulmonary remodeling and thus, have a role inthe development of pulmonary hypertension.

It is reminded that the NMDA receptor has been first discovered in thecentral nervous system playing a role in neurotransmission, neuronalplasticity and learning and memory. In addition it is involved inneurodegenerative diseases, such as Alzheimer disease and stroke.

More precisely, NMDA receptor is a specific type of ionotropic glutamatereceptor with a high permeability to calcium and a unique feature ofcontrolling numerous calcium-dependent processes, such as cellproliferation. Functional NMDA receptors are tetrameric assembliescomposed of multiple GluN1 subunits in combination with at least onetype of GluN2 to generate a large number of different NMDARs.

One way in which the functions of the various NMDAR subunits may beassessed is through the use of subunit selective agonists andantagonists and a number of pharmacological agents have already beenshown to distinguish between certain NMDAR subtypes. Memantine, MK-801(dizocilpine), dextrophan, aptiganel, ifenprodil, Ro-25-6981 are forexample representative NMDAR antagonists.

It is now known that NMDARs also play a role outside the CNS in variousperipheral systems, including bone, pancreas and skin, where they playimportant functions such as regulation of the bone mass, liberation ofinsulin and skin development (Skerry T M, Genever P G. Trends Pharmacol.Sci., 2001), and kidney function (Dryer S, Nephrol. Dial. Transplant.,2015). The expression of NMDA receptors has also been characterized inthe peripheral tissues, including the lung, the heart and the immunesystem.

At last, several studies have shown the utility of NMDA receptorantagonists to limit tumor growth (Takano T et al., Nature Medicine,2001, Rothstein J D et al., Nature Medicine, 2001, Rzeski W et al.,PNAS, 2001). However, NMDA receptor expression is not limited toglioblastoma and many tumors may express NMDA receptors.

Thus, NMDARs have a preeminent role in many physiological andpathological processes outside the CNS.

However, at the knowledge of the inventors there is no informationavailable about the development of peripheral NMDAR antagonists.

Otherwise, since the NMDA receptor has been first discovered in the CNS,the available NMDA receptor blockers, like in particular memantine andifenprodil, are essentially provided as neuroprotective drugs that areuseful in stroke, traumatic brain injury, epilepsy, Alzheimer disease,Parkinson disease, Huntington's chorea, and others involving the brainand or the spinal cord tissue.

Accordingly, NMDA receptor blockers produced so far are mainly designedand used with the intention that they will cross the blood brain barrierin order to treat neurological diseases.

Unfortunately, general blocking of NMDA receptors that could reach thebrain causes adverse effects such as ataxia, memory deficit,hallucination, cognitive disruption, psychotic-spectrum reaction andother neurological problems.

In particular, it is well known that the administration of antagonistDizocilpine causes psychotomimetic side effects, such as hallucinations,or hyperlocomotions (Joannes T. M. Linders et al., Letters in DrugDesign & Discovery, 2010, 7, 79-87). It also induces brain lesionscalled Olney's lesions, in test rats.

For these reasons, the antagonist Dizocilpine is mainly used in ananimal model to mimic psychosis for experimental purposes.

Thus, to date, most NMDAR antagonists that reached clinical developmentto treat neurodegenerative diseases cannot be used in the peripherywithout major central side-effects.

Indeed, it is not acceptable to use such drugs for treating a chronicdisease with peripheral NMDAR involvement, such as pulmonaryhypertension and in particular pulmonary arterial hypertension withsecondary deleterious toxic side effects on healthy brain tissues.

Therefore, there is a crucial need for new peripheral NMDAR blockers.

In particular, there is a need for new compounds selectively targetingthe peripheral NMDA receptor but not crossing the blood brain barrier.However, a minimized brain penetration to reduce undesirable CNSside-effects has not to be obtained in detriment of the expectedperipheral NMDARs blocking activity.

Furthermore, there is a need for new compounds acting as selectiveantagonists toward NMDARs, not crossing the blood-brain barrier andhaving a good aqueous solubility to be convenient at least foradministration.

More particularly, there is a need to provide new means of treating adisease with peripheral NMDAR involvement, such as pulmonaryhypertension and in particular pulmonary arterial hypertension.

The present invention precisely aims to provide novel compoundscomplying with the previous requirements.

Therefore, according to one of its aspects, the invention is directed tocompounds of formula (I):

wherein:

-   -   R₁ represents a hydrogen atom, a halogen atom, —OH, —CN, a        (C₁-C₆)alkyl group, a (C₂-C₆)alkenyl group, a (C₁-C₄)alkoxy        group, a —C(═NH)(—OH) group, a (C₁-C₄)alkyl-C(═NH)(—OH) group, a        —NH—CO—(C₁-C₄)alkyl group, a —NR₁₁R₁₂ group, a —NR₁₃R₁₄R₁₅        group, a (C₃-C₇)cycloalkyl group optionally substituted with a        5- or 6-membered aryl group, a 5- or 6-membered aryl group or a        5- to 12-membered heteroaryl group; said aryl or heteroaryl        group being optionally substituted with one or more halogen        atom, (C₁-C₆)alkyl group, (C₁-C₄)alkoxy group, or        trifluoromethyl group;    -   R₂ represents a (C₁-C₁₀)alkyl group, a (C₁-C₆)alkyl-OH group, a        (C₂-C₆)alkenyl group or a (C₂-C₆)alkynyl group;    -   n is 1, 2, 3, 4 or 5;    -   R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent, independently of        each other, a hydrogen atom, a halogen atom, —OH, —N₃, —SCF₃, a        trifluoromethyl group, a (C₁-C₆)alkyl group, a (C₁-C₆)alkoxy        group, a (C₁-C₆)alkyl-OH group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a 5- or 6-membered aryl group or a 5- to 12-membered        heteroaryl group;    -   R₁₁, R₁₂, R₁₃, R₁₄, and R₁₅ represent, independently of each        other, a hydrogen atom or a (C₁-C₆)alkyl group;    -   X⁻ is an anionic counterion, in particular chosen from I⁻, Cl⁻,        Br⁻, and OH⁻;        for use as a peripheral NMDA receptor antagonist.

Preferably, according to one of its aspects, the invention is directedto compounds of formula (I):

wherein:

-   -   R₁ represents a hydrogen atom, —OH, —CN, a (C₁-C₆)alkyl group, a        (C₁-C₄)alkoxy group, a —C(═NH)(—OH) group, a        (C₁-C₄)alkyl-C(═NH)(—OH) group, a —NH—CO—(C₁-C₄)alkyl group, a        —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅ group, a (C₃-C₇)cycloalkyl group        optionally substituted with a 5- or 6-membered aryl group, a 5-        or 6-membered aryl group or a 5- to 12-membered heteroaryl        group; said aryl or heteroaryl group being optionally        substituted with one or more halogen atom, (C₁-C₆)alkyl group,        (C₁-C₄)alkoxy group, or trifluoromethyl group;    -   R₂ represents a (C₁-C₁₀)alkyl group;    -   n is 1, 2, 3, 4 or 5;    -   R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent, independently of        each other, a hydrogen atom, a halogen atom, —OH, —N₃, —SCF₃, a        trifluoromethyl group, a (C₁-C₆)alkyl group, a (C₁-C₆)alkoxy        group, a (C₁-C₆)alkyl-OH group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a 5- or 6-membered aryl group or a 5- to 12-membered        heteroaryl group;    -   R₁₁, R₁₂, R₁₃, R₁₄, and R₁₅ represent, independently of each        other, a hydrogen atom or a (C₁-C₆)alkyl group;    -   X⁻ is an anionic counterion, in particular chosen from I⁻, Cl⁻,        Br⁻, and OH⁻;        for use as a peripheral NMDA receptor antagonist.

As detailed here-after, the inventors identified some chemicalmodifications which, when introduced in the parent molecule dizocilpine,allow to achieve compounds, new for some of them, that areadvantageously unable to cross the blood brain barrier but still exhibita selective and efficient peripheral NMDARs blocking activity.

As shown in the following examples, compounds according to formula (I)may advantageously have a Kp brain value measured in rat very low, bycontrast to dizocilpine which has a much greater Kp brain value.

It is reminded that in vivo equilibrium distribution between blood andbrain in rodents is the most commonly used parameter to evaluate brainpenetration. This parameter is defined as the ratio of concentrations inbrain and blood, Kp_(“brain”) (C_(brain)/C_(plasma)) or log(BB).

Log(BB) is the logarithm of the ratio of the steady-state totalconcentration of a compound in the brain to that in the blood/plasma,log(BB)=log(C_(brain)/C_(plasma)).

This parameter depends upon the passive diffusion characteristics, theimplication of membrane transporters at the BBB level and the relativedrug binding affinity differences between the plasma proteins and braintissue.

Generally, compounds with a brain/plasma ratio of greater than 0.5 areconsidered to have sufficient access to the central nervous system(CNS). Thus, compounds with a value greater than 1 freely cross the BBB.As shown in the following example 3, claimed compounds do not penetratethe central nervous system (CNS) in rat.

Thus, this property of not crossing the BBB is advantageously notdeleterious for the expected selective peripheral NMDARs blockingactivity.

Accordingly, the compounds according to the invention may be used asselective peripheral NMDA receptor antagonist for treating, withoutcentral side-effects, the conditions and diseases with peripheral NMDAreceptors involvement. Advantageously, they target peripheral NMDARs inthe three systems (cardiac, pulmonary, immune), notably involved in PH,and in particular in PAH, without central side-effects.

According to the invention, the term “central side-effects” encompassesadverse effects in particular on healthy brain tissues, such as ataxia,memory deficit, hallucination, cognitive disruption, psychotic-spectrumreaction and other neurological problems.

According to another of its aspects, the present invention also relatesto compounds of general formula (I):

wherein:

-   -   R₁ represents a hydrogen atom, a halogen atom, —OH, —CN, a        (C₁-C₆)alkyl group, a (C₂-C₆)alkenyl group, a (C₁-C₄)alkoxy        group, a —C(═NH)(—OH) group, a (C₁-C₄)alkyl-C(═NH)(—OH) group, a        —NH—CO—(C₁-C₄)alkyl group, a —NR₁₁R₁₂ group, a —NR₁₃R₁₄R₁₅        group, a (C₃-C₇)cycloalkyl group optionally substituted with a        5- or 6-membered aryl group, a 5- or 6-membered aryl group or a        5- to 12-membered heteroaryl group; said aryl or heteroaryl        group being optionally substituted with one or more halogen        atom, (C₁-C₆)alkyl group, (C₁-C₄)alkoxy group, or        trifluoromethyl group;    -   R₂ represents a (C₁-C₁₀)alkyl group, a (C₁-C₆)alkyl-OH group, a        (C₂-C₆)alkenyl group or a (C₂-C₆)alkynyl group;    -   n is 1, 2, 3, 4 or 5;    -   R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent, independently of        each other, a hydrogen atom, a halogen atom, —OH, —N₃, —SCF₃, a        trifluoromethyl group, a (C₁-C₆)alkyl group, a (C₁-C₆)alkoxy        group, a (C₁-C₆)alkyl-OH group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a 5- or 6-membered aryl group or a 5- to 12-membered        heteroaryl group;    -   R₁₁, R₁₂, R₁₃, R₁₄, and R₁₅ represent, independently of each        other, a hydrogen atom or a (C₁-C₆)alkyl group;    -   X⁻ is an anionic counterion, in particular chosen from I⁻, Cl⁻,        Br⁻, and OH⁻;        provided that when R₂ is a methyl group, R₃, R₄, R₅, R₆, R₇, R₈,        R₉ and R₁₀ are a hydrogen atom and n is 1, then R₁ is not a        hydrogen atom.

Preferably, the present invention also relates to compounds of generalformula

wherein:

-   -   R₁ represents a hydrogen atom, —OH, —CN, a (C₁-C₆)alkyl group, a        (C₁-C₄)alkoxy group, a —C(═NH)(—OH) group, a        (C₁-C₄)alkyl-C(═NH)(—OH) group, a —NH—CO—(C₁-C₄)alkyl group, a        —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅ group, a (C₃-C₇)cycloalkyl group        optionally substituted with a 5- or 6-membered aryl group, a 5-        or 6-membered aryl group or a 5- to 12-membered heteroaryl        group; said aryl or heteroaryl group being optionally        substituted with one or more halogen atom, (C₁-C₆)alkyl group,        (C₁-C₄)alkoxy group, or trifluoromethyl group;    -   R₂ represents a (C₁-C₁₀)alkyl group;    -   n is 1, 2, 3, 4 or 5;    -   R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent, independently of        each other, a hydrogen atom, a halogen atom, —OH, —N₃, —SCF₃, a        trifluoromethyl group, a (C₁-C₆)alkyl group, a (C₁-C₆)alkoxy        group, a (C₁-C₆)alkyl-OH group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a 5- or 6-membered aryl group or a 5- to 12-membered        heteroaryl group;    -   R₁₁, R₁₂, R₁₃, R₁₄, and R₁₅ represent, independently of each        other, a hydrogen atom or a (C₁-C₆)alkyl group;    -   X⁻ is an anionic counterion, in particular chosen from I⁻, Cl⁻,        Br⁻, and OH⁻;        provided that when R₂ is a methyl group, R₃, R₄, R₅, R₆, R₇, R₈,        R₉ and R₁₀ are a hydrogen atom and n is 1, then R₁ is not a        hydrogen atom.

According to another of its aspects, the invention is directed tocompounds of formula (I) according to the invention for use forpreventing and/or inhibiting and/or treating a disease or a condition inwhich the peripheral NMDA receptors are involved, like pulmonaryhypertension diseases and in particular pulmonary arterial hypertension.

According to the present invention, pulmonary hypertension diseasescover any pathologies trouble commonly identified under that name.According to this aspect, the present invention also covers any newgroup or subgroup of pulmonary arterial hypertension and pulmonaryhypertension, in particular as mentioned hereafter.

According to another of its aspects, the present invention is directedto a method of treatment and/or prevention of a disease or a conditionin which the peripheral NMDA receptors are involved, like pulmonaryhypertension diseases and in particular pulmonary arterial hypertension,comprising the administration of a compound of formula (I) according tothe invention.

Advantageously, the present invention is directed to a method ofprevention of a disease or a condition in which the peripheral NMDAreceptors are involved, like pulmonary hypertension diseases and inparticular pulmonary arterial hypertension, comprising theadministration of a compound of formula (I) according to the invention.

Indeed, compounds of formula (I) of the present invention are veryuseful as vascular protectors in prevention, for example inpre-operative or in the prevention of inflammation phenomena inextracorporeal circulation (ECC).

Within the meaning of the invention, the term “prevent” or “prevention”with respect to an event is intended to mean the decrease of a risk ofoccurrence of said event.

In the context of the present invention, the following abbreviations andempirical formulae are used:

-   -   ALI Acute Lung Injury    -   ARDS Acute Respiratory Distress Syndrome    -   BB Brain and Blood    -   BBB Blood-Brain Barrier    -   CDCl₃ Deuterated chloroform    -   CNS Central Nervous System    -   DMSO Dimethyl Sulfoxide    -   IR InfraRed    -   hPASMC Human Pulmonary Arterial Smooth Muscle Cells    -   HIRMS High Resolution Mass Spectroscopy    -   LiAlH₄ or LAH Lithium Aluminium Hydride    -   Na₂SO₄ Sodium Sulfate    -   NMDA N-Methyl-D-Aspartate    -   NMDAR N-Methyl-D-Aspartate Receptor    -   NMR Nuclear Magnetic Resonance    -   PAH Pulmonary Arterial Hypertension    -   PH Pulmonary Hypertension    -   RT-PCR Reverse Transcription Polymerase Chain Reaction    -   RVSP Right Ventricular Systolic Pressure    -   THF Tetrahydrofuran    -   TLC Thin Layer Chromatography    -   VWF Von Willebrand Factor

Other features and advantages of the invention will emerge more clearlyfrom the description and examples that follow.

Compounds of the Invention

As above-mentioned, the compounds used according to the inventioncorrespond to general formula (I):

wherein:

-   -   R₁ represents a hydrogen atom, a halogen atom, —OH, —CN, a        (C₁-C₆)alkyl group, a (C₂-C₆)alkenyl group, a (C₁-C₄)alkoxy        group, a —C(═NH)(—OH) group, a (C₁-C₄)alkyl-C(═NH)(—OH) group, a        —NH—CO—(C₁-C₄)alkyl group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a (C₃-C₇)cycloalkyl group optionally substituted with a        5- or 6-membered aryl group, a 5- or 6-membered aryl group or a        5- to 12-membered heteroaryl group; said aryl or heteroaryl        group being optionally substituted with one or more halogen        atom, (C₁-C₆)alkyl group, (C₁-C₄)alkoxy group, or        trifluoromethyl group;    -   R₂ represents a (C₁-C₁₀)alkyl group, a (C₁-C₆)alkyl-OH group, a        (C₂-C₆)alkenyl group or a (C₂-C₆)alkynyl group;    -   n is 1, 2, 3, 4 or 5;    -   R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent, independently of        each other, a hydrogen atom, a halogen atom, —OH, —N₃, —SCF₃, a        trifluoromethyl group, a (C₁-C₆)alkyl group, a (C₁-C₆)alkoxy        group, a (C₁-C₆)alkyl-OH group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a 5- or 6-membered aryl group or a 5- to 12-membered        heteroaryl group;    -   R₁₁, R₁₂, R₁₃, R₁₄, and R₁₅ represent, independently of each        other, a hydrogen atom or a (C₁-C₆)alkyl group;    -   X⁻ is an anionic counterion, in particular chosen from I⁻, Cl⁻,        Br⁻, and OH⁻.

Preferably, the compounds used according to the invention correspond togeneral formula (I):

wherein:

-   -   R₁ represents a hydrogen atom, —OH, —CN, a (C₁-C₆)alkyl group, a        (C₁-C₄)alkoxy group, a —C(═NH)(—OH) group, a        (C₁-C₄)alkyl-C(═NH)(—OH) group, a —NH—CO—(C₁-C₄)alkyl group, a        —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅ group, a (C₃-C₇)cycloalkyl group        optionally substituted with a 5- or 6-membered aryl group, a 5-        or 6-membered aryl group or a 5- to 12-membered heteroaryl        group; said aryl or heteroaryl group being optionally        substituted with one or more halogen atom, (C₁-C₆)alkyl group,        (C₁-C₄)alkoxy group, or trifluoromethyl group;    -   R₂ represents a (C₁-C₁₀)alkyl group;    -   n is 1, 2, 3, 4 or 5;    -   R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent, independently of        each other, a hydrogen atom, a halogen atom, —OH, —N₃, —SCF₃, a        trifluoromethyl group, a (C₁-C₆)alkyl group, a (C₁-C₆)alkoxy        group, a (C₁-C₆)alkyl-OH group, a —NR₁₁R₁₂ group, a —N⁺R₁₃R₁₄R₁₅        group, a 5- or 6-membered aryl group or a 5- to 12-membered        heteroaryl group;    -   R₁₁, R₁₂, R₁₃, R₁₄, and R₁₅ represent, independently of each        other, a hydrogen atom or a (C₁-C₆)alkyl group;    -   X⁻ is an anionic counterion, in particular chosen from I⁻, Cl⁻,        Br⁻, and OH⁻.

The compounds of formula (I) may comprise one or more asymmetric carbonatoms. They may thus exist in the form of enantiomers ordiastereoisomers. These enantiomers and diastereoisomers, and alsomixtures thereof, including racemic mixtures, form part of theinvention.

In the context of the present invention, the following definitionsapply:

-   -   C_(t)-C_(z): a carbon-based chain possibly containing from t to        z carbon atoms in which t and z may take values from 1 to 10;        for example, C₁-C₆ is a carbon-based chain possibly containing        from 1 to 6 carbon atoms.    -   an alkyl: a linear or branched saturated aliphatic group, in        particular comprising from I to 6 carbon atoms. Examples that        may be mentioned include methyl, ethyl, n-propyl, isopropyl,        n-butyl, isobutyl, tert-butyl, n-pentyl, etc. . . .    -   an alkenyl: a linear or branched unsatured or partially        unsaturated aliphatic group containing conjugated or        non-conjugated double bond(s). Examples that may be mentioned        include ethylenyl, propenyl, but-1-enyl, but-2-enyl . . .    -   an alkynyl: a linear or branched unsatured or partially        unsaturated aliphatic group containing conjugated or        non-conjugated triple bond(s). Examples that may be mentioned        include ethynyl, propynyl, but-1-ynyl, but-2-ynyl . . .    -   an alkoxy: a radical —O-alkyl in which the alkyl group is as        defined previously.    -   a halogen atom: an atom chosen among Fluorine, Chlorine,        Bromine, and Iodine.    -   a cycloalkyl group: a non aromatic mono- or bicyclic saturated        or partially saturated or unsaturated ring containing 3 to 8        carbon atoms. Examples of cycloalkyl group that may be mentioned        include cyclopropane, cyclobutane, cyclopentane, cyclopentene,        cyclohexane or cyclohexene.    -   an aryl: a monocyclic or bicyclic aromatic group containing 5 or        6 carbon atoms. By way of examples of an aryl group, mention may        be made of phenyl or naphthyl group. Preferably, the aryl group        is phenyl.    -   a heteroaryl: a 5- to 12-membered monocyclic or bicyclic        aromatic group containing from 1 to 5 heteroatoms chosen from O,        S and N. Examples of monocyclic heteroaryls that may be        mentioned include imidazolyl, pyrazolyl, thiazolyl, oxazolyl,        isothiazolyl, isoxazolyl, furyl, thienyl, oxadiazolyl,        thiadiazolyl, triazolyl, tetrazolyl, pyridinyl, pyrazinyl,        pyrimidinyl, pyridazinyl and triazinyl. Examples of bicyclic        heteroaryls that may be mentioned include indolyl, isoindolyl,        benzofuryl, benzothiophenyl, benzoxazolyl, benzimidazolyl,        indazolyl, benzothienyl, isobenzofuryl, isobenzothiazolyl,        pyrrolo[2,3-c]pyridyl, pyrrolo[2,3-b]pyridyl,        pyrrolo[3,2-b]pyridyl, pyrrolo[3,2-c]pyridyl,        pyrrolo[1,2-a]pyridyl, quinolyl, isoquinolyl, cinnolinyl,        quinazolinyl, quinoxalinyl, pyrrolo[1,2-a]imidazolyl,        imidazo[1,2-a]pyridyl, imidazo[1,2-a]pyridazinyl,        imidazo[1,2-c]pyrimidinyl, imidazo[1,2-a]pyrimidinyl,        imidazo[1,2-a]pyrazinyl, imidazo[4,5-b]pyrazinyl,        imidazo[4,5-b]pyridyl, imidazo[4,5-c]pyridyl,        pyrazolo[2,3-a]pyridyl, pyrazolo[2,3-a]pyrimidinyl,        pyrazolo[2,3-a]pyrazinyl, thiazolo[5,4-b]pyridyl,        thiazolo[5,4-c]pyridyl, thiazolo[4,5-c]pyridyl,        thiazolo[4,5-b]pyridyl, oxazolo[5,4-b]pyridyl,        oxazolo[5,4-c]pyridyl, oxazolo[4,5-c]pyridyl,        oxazolo[4,5-b]pyridyl, isothiazolo[5,4-b]pyridyl,        isothiazolo[5,4-c]pyridyl, isothiazolo[4,5-c]pyridyl,        isothiazolo[4,5-b]pyridyl, isoxazolo[5,4-b]pyridyl,        isoxazolo[5,4-c]pyridyl, isoxazolo[4,5-c]pyridyl and        isoxazolo[4,5-b]pyridyl. The heteroaryl groups may be more        preferably chosen among quinolyl or pyridinyl groups.

According to a preferred embodiment, R₁ represents —OH, a (C₁-C₆)alkylgroup, a (C₂-C₆)alkenyl group, or a (C₃-C₇)cycloalkyl group.

According to a preferred embodiment, R₁ represents —OH, a (C₁-C₆)alkylgroup, or a (C₃-C₇)cycloalkyl group.

According to one embodiment, R₁ represents —OH. Advantageously, when R₁represents —OH, n is 2.

According to another embodiment, R₁ represents a (C₁-C₆)alkyl group.

According to another embodiment, R₁ represents a (C₃-C₇)cycloalkylgroup.

According to a preferred embodiment, R₂ represents a methyl group or anethyl group.

According to one embodiment, R₂ represents a methyl group.

According to another embodiment, R₂ represents an ethyl group.

According to a preferred embodiment, n is 1 or 2.

According to one embodiment, n is 1.

According to another embodiment, n is 2.

Preferably, R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ are a hydrogen atom.

According to a preferred embodiment, the anionic counterion X⁻ is anorganic or inorganic anionic counterion, especially chosen from I⁻, Cl⁻,Br⁻, and OH⁻.

Preferably, the anionic counterion X⁻ is chosen from Br⁻, I⁻ and Cl⁻,and more preferably chosen from I⁻ and Cl⁻.

More preferably, the anionic counterion is I⁻.

More preferably, the anionic counterion is Cl⁻.

More preferably, the anionic counterion is Br⁻.

It is clear that features of the above-mentioned embodiments may becombined with each other, unless specifically noted otherwise.

Among the compounds of general formula, mention may be made especiallyof the following compounds:

More preferably, among the compounds of general formula, mention may bemade especially of the following compounds:

More preferably, among the compounds of general formula, mention may bemade especially of the following compounds:

Preparation of the Compounds of the Invention

The compounds of the invention may be prepared according to methodswell-known by the skilled artisan, as illustrated in the examples thatfollow.

According to a first embodiment, the synthesis of compounds of thepresent invention may be accomplished according to Scheme 1 below.

According to another embodiment, the synthesis of compounds of thepresent invention may be accomplished according to Scheme 2 below.

Applications

As specified previously and clearly illustrated by the followingexamples, the compounds according to the present invention are useful asperipheral NMDA receptor antagonists.

The present invention therefore provides a method for preventing and/orinhibiting and/or treating a disease or a condition in which theperipheral NMDA receptors are involved, comprising at least a step ofadministering to an individual in need thereof at least an effectiveamount of at least one compound in accordance with the invention.

In particular, the disease or the condition may be chosen amongpulmonary hypertension, such as pulmonary arterial hypertension orthromboembolic pulmonary hypertension, pulmonary diseases involvinginflammation, fibrosis and remodeling such as asthma, non-neuronalcancers such as colon, breast, lung or thyroid carcinoma, diabetes,atherosclerosis, sickle cell disease, diseases involving thrombosis,acute infections such as ARDS syndrome or ALI, chronic infectiousdiseases such as gastric ulcer induced by Helicobacter pylori,inflammatory/autoimmune diseases such as rheumatoid arthritis andirritable Bowel syndrome and osteoarthritis, heart failure, arrhythmias,renal disorders, pain, in particular peripheral neuropathic pain,psoriasis, atopic dermatitis and osteoporosis.

As mentioned above, pulmonary hypertension covers five groups ofdiseases.

The first group is pulmonary arterial hypertension. PAH may beassociated with idiopathic and heritable PAH (bone morphogenetic proteinreceptor type 2 (BMPR2), ALK-1, Endoglin (ENG), SMAD9, Caveolin-1(CAV1), KCNK3), with drug- and toxin-induced PAH, with connective tissuediseases, with human immunodeficiency virus, with portal hypertension,with congenital heart diseases, with schistosomiasis, with pulmonaryveno-occlusive disease, pulmonary capillary hemangiomatosis, andpersistent PH of the newborn.

The second group is PH due to left heart disease. It encompasses themost frequent form of PH, i.e. left ventricular systolic dysfunction,left ventricular diastolic dysfunction, valvular disease andcongenital/acquired left heart inflow/outflow tract obstruction andcongenital cardiomyopathies.

The third group is PH due to lung diseases and/or hypoxia. This groupcomprises patients with parenchymal lung diseases or other causes ofhypoxia in whom the presence of PH is considered directly related tothese underlying diseases. More particularly, it comprises chronicobstructive pulmonary disease, interstitial lung disease, otherpulmonary diseases with mixed restrictive and obstructive pattern,sleep-disordered breathing, alveolar hypoventilation disorders, chronicexposure to high altitude and development lung diseases.

The fourth group is chronic thromboembolic pulmonary hypertension.

The fifth group is PH with unclear or multifactorial mechanisms.Included in this group are numerous forms of PH in which multiplepathophysiological mechanisms might be implicated in the elevation inpulmonary vascular pressures. It encompasses hematologic disorders(chronic haemolytic anemia, myelo-proliferative disorders, splenectomy),systemic disorders (sarcoidosis, pulmonary histiocytosis,lymphangioleiomyomatosis), metabolic disorders (glycogen storagedisease, Gaucher disease, thyroid disorders) and others such as tumoralobstruction, fibrosing mediastinitis, chronic renal failure andsegmental PH.

Of course, this recent classification is constantly evolving, and newgroups and/or subgroups, also covered in the context of the presentinvention, are regularly discovered.

More specifically, according to the present invention, the disease orthe condition is pulmonary hypertension, such as pulmonary arterialhypertension or thromboembolic pulmonary hypertension, and preferablypulmonary arterial hypertension.

The compounds according to the invention may be used for the preparationof medicaments.

Thus, according to yet another of its aspects, the present inventionrelates to a medicament comprising as pharmaceutical active agent atleast one compound according to the invention.

In other words, the present invention relates to a compound according tothe invention for use as a medicament.

According to another of its aspects, the present invention relates to apharmaceutical composition comprising at least one compound according tothe invention, and at least one pharmaceutically acceptable excipient.

According to one embodiment, a pharmaceutical composition of theinvention may be intended to be administered separately, sequentially orsimultaneously with an agent useful for the prevention and/or theinhibition and/or the treatment of a disease condition, said agent beingdifferent from the compound of formula (I) of the invention.

Thus, the present invention also relates to a pharmaceutical compositioncomprising at least one compound according to the invention incombination with at least one other therapeutic agent, and at least onepharmaceutically acceptable excipient.

According to one embodiment, the compounds of the present invention maybe used alone or combined with one other therapeutic agent, for examplevasodilator agents, other glutamate receptor antagonists (ionotropicand/or metabotropic), and in particular other NMDAR antagonists,chemotherapeutic agents, other pulmonary hypertension regimen orradiotherapeutic regimen and their mixtures.

Preferably, the present invention relates to a pharmaceuticalcomposition comprising at least one compound according to the inventionin combination with at least one other therapeutic agent, and preferablywith vasodilator agents and/or other glutamate receptor antagonists(ionotropic and/or metabotropic), and in particular other NMDARantagonists.

In the meaning of the present invention, “glutamate receptorantagonists” comprises two families: ionotropic (ion channels) andmetabotropic (receptors with seven transmembrane domains). Amongionotropic, there are NMDAR, AMPA and Kainates. Ionotropic andmetabotropic families are more particularly defined in the Guide toPharmacology (IUPHAR/BPS).

Thus, according to one embodiment, a method of the invention maycomprise the step of administering a compound of formula (I) inaccordance with the invention, separately, sequentially orsimultaneously with another therapeutic agent, and preferably withvasodilator agents and/or other glutamate receptor antagonists(ionotropic and/or metabotropic), and in particular NMDAR antagonists.

With respect to the use of the claimed compounds, in particular fortreating pulmonary hypertension, it may be particularly advantageous tocombine them with another or several others conventional therapeuticactive(s) already considered in the treatment of such diseases. Sincethe claimed compounds acts according a specific new route, it may beexpected to achieve a better result by simultaneously acting throughdifferent therapeutic routes.

In particular, this embodiment may allow reducing the therapeutic dosesof respective compounds of the present invention, to administrate to thepatient, thus allowing less adverse effects. In addition, thisembodiment allows achieving additive or synergistic effect of therespective combined compounds of the present invention.

Thus, the present invention is also directed to a method of treatment ofpulmonary hypertension, and in particular pulmonary arterialhypertension, comprising the administration of a claimed compound,advantageously combined with the administration of at least one activeagent selected among the group consisting of vasodilator agents, otherglutamate receptor antagonists (ionotropic and/or metabotropic), and inparticular other NMDAR antagonists, chemotherapeutic agents, otherpulmonary hypertension regimen or radiotherapeutic regimen and theirmixtures.

For example, the compounds of the present invention may be used combinedwith endothelin receptor antagonists (ERAs), such as bosentan(Tracleer™, Actelion) and ambrisentan (Letairis™, Gilead), prostacyclinderivatives such as epoprostenol (Flolan™ Gsk, Actelion), treprostinil(Remodulin™, United Therapeutics) and Iloprost™ (Actelion), or PDE5inhibitors such as Sildenafil (Revatio™, Pfizer) and Tadalafil(Adcirca™, Lilly).

As examples of chemotherapeutic agents that may be suitable for theinvention, one may mention chemotherapeutic agents chosen fromalkylating agents, intercalating agents, antimicrotubule agents,antimitotics, antimetabolites, antiproliferative agents, antibiotics,immunomodulatory agents, anti-inflammatories, kinases inhibitors,anti-angiogenic agents, antivascular agents, oestrogenic and androgenichormones.

A radiotherapeutic regimen may be administrated by exposing anindividual in need thereof to a source of ionizing radiation such asX-ray, gamma-ray or beta-ray.

The pharmaceutical compositions may contain more particularly aneffective dose of at least one compound according to the invention.

An “effective dose” means an amount sufficient to induce a positivemodification in the condition to be regulated or treated, but low enoughto avoid serious side effects. An effective amount may vary with thepharmaceutical effect to obtain or with the particular condition beingtreated, the age and physical condition of the end user, the severity ofthe condition being treated/prevented, the duration of the treatment,the nature of other treatments, the specific compound or compositionemployed, the route of administration, and like factors.

A compound of formula (I) according to the invention may be administeredin an effective dose by any of the accepted modes of administration inthe art.

In one embodiment, a compound of the invention may be used in acomposition intended to be administered by oral, nasal, sublingual,aural, ophthalmic, topical, rectal, vaginal, urethral, or parenteralinjection route.

The route of administration and the galenic formulation will be adaptedby one skilled in the art pursuant to the desired pharmaceutical effect.

One of ordinary skill in the art of therapeutic formulations will beable, without undue experimentation and in reliance upon personalknowledge, to ascertain a therapeutically effective dose of a compoundof the invention for a given indication.

A pharmaceutical composition of the invention may be formulated with anyknown suitable pharmaceutically acceptable excipients according to thedose, the galenic form, the route of administration and the likes.

As used herein, “pharmaceutically acceptable excipients” include any andall solvents, dispersion media, coatings, antibacterial and antifungalagents, isotonic and absorption delaying agents and the like. Exceptinsofar as any conventional excipient is incompatible with the activecompounds, its use in a medicament or pharmaceutical composition of theinvention is contemplated.

A medicament or pharmaceutical composition of the invention may be inthe form of tablets, pills, powders, lozenges, sachets, cachets,elixirs, suspensions, emulsions, solutions, syrups, aerosols, sprays,ointments, gels, creams, sticks, lotions, pastes, soft and hard gelatinecapsules, suppositories, sterile injectable solutions, sterile packagespowders and the like.

The present invention will be better understood by referring to thefollowing examples and figures which are provided for illustrativepurpose only and should not be interpreted as limiting in any manner theinstant invention.

FIGURES

FIG. 1: Effect of NMDAR knockout in smooth muscle cells on thedevelopment of pulmonary hypertension. NMDAR knockout in smooth musclecells attenuates hemodynamic and cardiac parameters of pulmonaryhypertension as assessed by measurement of right ventricular systolicpressure and Fulton index. Right ventricular systolic pressure (RVSP)measurement in wild-type mice (n=8-14) and mice with a knockout of NMDARin SMCs (n=7-13) after 3 weeks of normoxia or chronic hypoxia (FiO₂:10%). Ratio of right ventricle weight to left ventricle plus septumweight (Fulton index) for wild-type mice (n=12) and mice with a knockoutof NMDAR in SMCs (n=8-12) after 3 weeks of normoxia or chronic hypoxia(FiO₂:10%).

FIG. 2: Effect of NMDAR knockout in smooth muscle cells on thedevelopment of pulmonary hypertension. NMDAR knockout in smooth musclecells attenuates vascular remodeling of pulmonary hypertension asassessed by morphometric analysis. Morphometric analysis of pulmonaryvessels in wild-type mice (n=5) and mice with a knockout of NMDAR inSMCs (n=5) after 3 weeks of normoxia or chronic hypoxia (FiO2: 10%).Same experiment as in FIG. 1. Pulmonary vessels were assigned to fourgroups on the basis of external vessel diameter (<30 μm, 30 μm to 50 μm,50 μm to 75 μm and 75 μm to 125 μm). Each vessel was classified asnon-muscularized (VWF+, α-smooth muscle actin-), partially muscularized(VWF+, α-smooth muscle actin+/−), or fully muscularized (VWF+, α-smoothmuscle actin+). Statistical significance was determined by aMann-Whitney test (a), regular two-way ANOVA followed by Bonferonni'stests (b-d), a one-way ANOVA followed by Bonferroni's multiplecomparison tests (e). *P<0.05, **P<0.01, ***P<0.001 versus WT/control(a-d) or § § § P<0.001 versus control, ***P<0.001 versus PDGF (e). Thevalues shown are means±SEM (a-e).

FIG. 3: Measures of brain/plasma ratio (Kp_(“brain”)) of MK801, CompoundN^(o) 1 and Compound N^(o) 26 in rat. The results are expressed as themean values obtained from 3 rats for each compound. Bars representstandard deviations. Kp_(“brain”) MK-801=17.7 1.75. Kp_(“brain”)Compound N^(o) 1=0.3±0.03. Kp_(“brain”) Compound N^(o) 26=0.4±0.08.

EXAMPLES

Methods

Animal Models of Pulmonary Hypertension

All animals were used in strict accordance to the European Unionregulations (Directive 2010/63/UE) for animal experiments. All animalswere maintained in a temperature and humidity-controlled room with a 12hours/12 hours light/dark cycle with access to a standard chow and waterad libitum.

Following procedures performed on mice, were approved by the ethicalcommittee CEEA26 (Animal experimentation ethic committee N^(o) 26) andthe French ministry of higher education and research.

Transgenic mice strains used are B6.129S4-Grin1tm2Stl/J (further namedas GRIN1fl/fl mice), B6.129S6-Taglntm2(cre)Yec/J (further named asTagln-cre mice) (both from JACKSON LABORATORY) andB6.Cg-Tg(Tek-cre/ERT2)1Arnd/ArndCnrm (further named as Tek-cre mice)(EUROPEAN MOUSE MUTANT ARCHIVE).

Briefly, GRIN1fl/fl mice were crossed with either Tek-cre mice ortagln-cre mice. For NMDAR knocked out in smooth muscle cells,experiments were performed on male Tagln-cre x GRIN1fl/fl mice and maleTagln-cre mice were used as controls. For NMDAR knocked out inendothelial cells, experiments were performed on male Tek-cre xGRIN1fl/fl mice and male Tek-cre mice were used as controls after 5weeks of Tamoxifen-containing chow (HARLAN LABORATORIES) administrationfollowed by 1 week of standard chow. In both experiments, pulmonaryhypertension was induced exposing mice to 3 weeks of hypoxia (10% FiO₂).Then, mice were submitted to anesthesia induced by inhalation ofisoflurane 3% mixed with air and maintained decreasing isofluraneconcentration between 1% and 1.5%. The heart was taken out the thoraciccage, auricles were removed and right ventricles were separated fromleft ventricles associated to septa. The weight of each part wasmeasured and the ratio of the right ventricle weigh to the leftventricle with septum weigh was calculated for each mouse. Lungs wereprocessed inflating them with 10 mL of a mixture of saline and OCT 1/1ratio (Shandon™ Cryomatrix™, THERMOFISCHER SCIENTIFIC). Ventricles andinflated lungs were then frozen in cooled isopentane (VWR) and stored at−80° C.

Morphometric Analysis

6 μm thick sections of mouse lungs were cut with a cryomicrotome (LEICAMICROSYSTEMS). Sections were allowed to dry during 1 hour under a hood.Then, they were fixed in cold acetone for 10 minutes. 10% goat serumplus 5% mouse serum were incubated for 1 hour to prevent unspecificbinding of antibodies. Anti-VWF and Anti-alpha smooth muscle cell-FITCantibodies were incubated in presence of 2% mouse serum during 1 hour atroom temperature. A negative control was performed omitting primaryantibodies. The secondary antibody was incubated during 30 minutes inpresence of 2% mouse serum. DAPI (LIFE TECHNOLOGIES) diluted at 1/500was incubated during 1 minute. Glass slides were finally mounted usingDako Fluorescent mounting medium (DAKO). Sections were then analyzedusing Eclipse 80i microscope coupled to Nis Elements BR2.30 software(NIKON).

For morphometric analysis performed on mouse lungs, intrapulmonaryarterioles were divided in four groups based on their external diameter:less than 30 μm, from 30 μm to 50 μm, from 50 μm to 75 μm and from 75 μmto 125 m. 20 arterioles per category identified with the VWF stainingwere qualified as non muscularized, partially muscularized or fullymuscularized based on the alpha smooth muscle actin staining. 5mice/group were included in the study.

In Vivo Brain Penetration Measurement: Drug Administration and Samplingof Brain and Plasma

The femoral vein of male Sprague-Dawley rats (CRL) weighing around 250 gwas surgically catheterized at least 72 hours prior to the experiment. 3animals were performed for each compound tested. The drug wasadministered as 3.45 h constant-rate intravenous infusion to approachsteady state, using a flow rate of 0.8 mL/h, corresponding to dosage of4 mg/kg (1.067 mg/kg/h, i.e. 1 mg/rat of ˜250 g). The vehicle used wassaline.

At the end of the infusion, the rats were anesthetized by inhalation ofisoflurane, and blood was collected in a heparinized tube from theabdominal aorta, followed by immediate rinsing of the bloodstream for 2minutes with saline at a rate of 15 mL/min using a peristaltic pump andleft intraventricle cannula (flowing via right atrium). The brain(without cerebellum) was removed, and transferred in a tube andhomogenized in two volumes of deionized water using a tissue homogenizer(Precellys24). All samples were stored at −20° C. until analysis. Plasmaand brain homogenate sample preparation was performed using solid phaseextraction on OASIS® WCX (Waters) and compounds were quantified byreversed phase liquid chromatography and positive electrosprayionization and multiple reaction monitoring mass spectrometry(LC-MS/MS).

Cultures of Hippocampal Neurons

For hippocampal neurons isolation and culture, all animals were used instrict accordance to the European Union regulations (Directive2010/63/UE) for animal experiments. 18 day-pregnant female Wistar ratswere decapitated, and fetuses were rapidly extracted from uterus andtransferred in dissection solution (50 ml PBS (LIFE TECHNOLOGIES)+50units/ml penicillin-streptomycin (Abx) (THERMOFISCHER SCIENTIFIC)+0.6%glucose. The rat fetus brains were quickly removed and placed indissection solution before hippocampus extraction. Hippocampus werecollected in HBSS (43.5 ml PBS, 0.6% glucose, 100 mM HEPES (LIFETECHNOLOGIES), 100 units/ml Abx) and digested by addition of 0.25%trypsin (LIFE TECHNOLOGIES) and 0.1% DNAse I. After 10 minutesincubation at 37° C., 10% FBS (THERMOFISCHER SCIENTIFIC) was added tostop digestion. Cells were then mechanically dissociated by gentlepipetting to obtain uniform suspension. After centrifugation (10minutes, 100 G) supernatant was removed and cell pellet was suspended inHC medium (50 ml neurobasal medium, 1 ml B27 supplement, 500 μlglutamine 200 mM 100× (all from LIFE TECHNOLOGIES), 50 units/ml Abx)plus 10% FBS and without Abx. Cells were counted and 630,000 cells weredispatched in each poly-D-lysine-coated 35 mm petri dishes (BD Falcon,CORNING) containing 2 ml HC for culture. After 6 days of culture,cytosine β-D-arabinofuranoside (Ara-C) was added to inhibitproliferation of glial cells. Cells were then used from DIV 14. Cellswere cultured at 37° C. in a humidified atmosphere of 5% CO₂ and 95%air.

Electrophysiology

Chemicals used for patch-clamp solutions were provided by Sigma-Aldrich.TTX was provided by R&D, CNQX by Abcam. Whole-cell voltage clamprecordings from rat hippocampal neurons were made with patch pipettes(5-6 MΩ) filled with intracellular solution (in mM): 150 CsCl, 5 EGTA,10 HEPES; its pH was adjusted to 7.2 with NaOH. The external bathsolution contained (in mM): 140 NaCl, 3 KCl, 2 CaCl₂, 10 HEPES, 10glucose, 0.5 μM TTX, 20 μM picrotoxin and 20 μM CNQX; its pH wasadjusted to 7.4 with CsOH. The membrane potential was clamped at −60 mV.Currents were monitored using an AxoPatch200B patch clamp amplifier(Axon Instruments, Sunnyvale, Calif., USA) filtered at 2 kHz anddigitized at 100 Hz. Experiments were controlled by data acquisitionboard (National Instruments). Data were analyzed by Exel and GraphPadsoftware. Liquid junction potentials were measured with the patch clampamplifier. Transmembrane currents were evoked in acutely isolatedneurons by the application of 100 μM NMDA and 20 μM D-serine.Antagonists of NMDA receptors were applied at increasing concentration.Cells were constantly perfused using gravity-fed bath at 1-2 ml/min. Tocalculate the percentage block by antagonist, residual desensitizationof NMDA-induced currents was compensated by fitting exponentials to thepre-antagonist portion of traces.

Statistical Analysis

Results are expressed as mean+SEM of measurement unless otherwiseindicated. Gaussian distribution of all data was assessed usingKolmogorov-Smirnov test or Shapiro-Wilk depending on sample size. Tocompare two groups of data, either unpaired t test or Mann-Whitney testwere used depending on the data distribution. For multiple comparisons,one-way analysis of variance followed by Bonferroni test orKruskal-Wallis followed by Dunn's tests were used when it wasappropriate. Results from transgenic mice were analyzed with a two-wayanalysis of variance followed by a Bonferroni test. Differences wereconsidered significant with a P value <0.05. Statistical analysis wasperformed with Prism 6 (GRAPHPAD SOFTWARE) and Excel softwares.

Example 1

Preparation of the Compounds According to the Invention

In accordance with the invention, the preparation of compounds ofgeneral formula (I) is illustrated below.

General Procedure A for the Preparation of1-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ketone

To a solution of 258 mg of MK801 hydrochloride (1 mmol) in 10 mL of dryDCM were added 1.5 equivalent of the corresponding acyl chloride, 20 mol% of DMAP and 3 equivalent of TEA under argon. The mixture was stirredat room temperature for 12 hours to 20 hours (reaction monitored byTLC). 50 mL of diethyl ether was added to the reaction mixture. Thesolution obtained was washed two times with 15 mL of saturated aqueoussolution of NH₄Cl. Organic layers were dried over sodium sulfate,concentrated under reduce pressure, at 10 mbar, and the crude productwas purified by column chromatography on silica gel.

General Procedure B for Reduction of1-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ketone

To 1 equivalent of a solution of MK801 amide derivative in 0.2 M ofanhydrous THF was added 5 equivalent of LiAlH₄ under argon atmosphere at0° C. After stirring at room temperature for an additional period of 30minutes, the mixture was heated at reflux for 12 hours to 24 hours(reaction monitored by TLC). After being allowed to cool to roomtemperature, the mixture was treated with drop-to-drop addition of waterat 0° C. till complete destruction of excess LAH. The mixture was thenfiltered on celite pad, washed with diethyl ether and the resultantsolution was washed with brine. After drying over sodium sulfate,evaporation of the solvent under reduced pressure, at 10 mbar, the aminewas directly engaged in the next step without purification.

General Procedure C for Preparation of(5S,10R)-12-CH₂R-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene

To 1 equivalent of a solution of MK801 maleate in 0.1 M of anhydrousacetonitrile were added 3.5 equivalent of K₂CO₃ and 1.1 equivalent ofRCH₂X under argon atmosphere, at room temperature. After stirring atreflux for 12 hours (reaction monitored by TLC), and after being allowedto cool to room temperature, the mixture was filtered on celite pad andwashed with ethyl acetate. After evaporation of the solvents underreduced pressure, at 10 mbar, the amine was directly engaged in the nextstep without purification.

General Procedure D for Quaternerization of(5S,10R)-12-CH₂R-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene

To a solution of 1 equivalent of the corresponding amine in 0.2 M ofdioxane in a microwave-type tube, was added 80 equivalent of alkyliodide. The vial is sealed, and the mixture was heated at 50° C. or 100°C. under stirring for 12 hours/or stirred at room temperature for fourdays. After being allowed to cool to room temperature, the precipitateformed was increased by addition of pentane and filtered on sinteredfilter and washed with ethyl acetate, then recovered by dissolution indichloromethane. The obtained solution was concentrated under reducedpressure, at 10 mbar, to give the desired quaternized ammonium iodidesalt, eventually purified over preparative plate.

Compound N^(o) 1

Compound N^(o) 1 is prepared according to the general procedure D.

To a solution of 674 mg of (+)-MK801 maleate (2 mmol) in 5 mL of dioxanewere added 2.59 g of cesium carbonate (8 mmol) and 5 mL of methyl iodide(80.3 mmol) to give 720 mg of Compound N^(o) 1 as a white solid withoutpurification.

Yield: 98%.

Melting point=270-280° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.52 (br d, J=6.9 Hz, 1H), 7.41-7.27(m, 5H), 7.15-7.09 (m, 2H), 6.37 (d, J=5.0 Hz, 1H), 3.99 (dd, J=18.8 Hz,5.9 Hz, 1H), 3.55 (s, 3H), 3.44 (s, 3H), 3.11 (d, J=18.8 Hz, 1H), 2.19(s, 3H).

¹³C NMR δ (75 MHz, MeOH d4) (ppm): 144.8, 137.4, 136.1, 131.5, 131.2(2C), 131.0, 130.6, 129.3, 125.1, 124.9, 122.2, 82.8, 75.9, 42.7, 32.4(2C), 12.6.

IR (neat) (cm⁻¹): λ_(max)=3462, 3042, 3007, 2949, 1612, 1478, 1461,1429, 1391, 1318, 1262, 1237, 1167, 1084, 1006, 971, 932, 809, 787, 768,718.

HRMS (ESI positive):

Calculated for C₁₈H₂₀N [M−I]⁺ 250.1596; Found 250.1592.

[α]_(D) ²⁰+190° (c 0.50, MeOH).

Compound N^(o) 2

Compound N^(o) 2 is prepared according to the general procedure D.

To a solution of 122 mg of(5S,10R)-12-ethyl-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane were added 2.5 mL of methyl iodide (40.2mmol) to give 128 mg of Compound N^(o) 2 as a white solid withoutpurification.

Yield: 64%.

Melting point=230-232° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.7-7.63 (m, 1H), 7.41-7.35 (m, 1H),7.35-7.23 (m, 4H), 7.14-7.06 (m, 2H), 6.07 (d, J=5.3 Hz, 1H), 3.77-3.6(m, 2H), 3.5-3.36 (m, 1H), 3.29 (s, 3H), 3.15 (d, J=19.0 Hz, 1H), 2.26(s, 3H), 1.65 (t, J=7.2 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.2, 135.2, 134.4, 130.4, 130.1,130.0 (2C), 129.2, 128.4, 124.4, 123.8, 120.6, 82.7, 71.2, 49.7, 45.9,31.6, 14.1, 10.5.

IR (neat) (cm⁻¹): λ_(max)=3462, 3010, 2944, 2839, 1613, 1478, 1452,1425, 1398, 1307, 1275, 1252, 1132, 1088, 1042, 1028, 965, 903, 811,768, 751, 667.

HRMS (ESI positive):

Calculated for C₁₉H₂₂N [M−I]⁺ 264.1752; Found 264.1749.

[α]_(D) ²⁰+178° (c 0.50, MeOH).

Compound N^(o) 3

Compound N^(o) 3 is prepared according to the general procedure D.

To a solution of 70 mg of(5S,10R)-12-butyl-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.25 mmol) in 1 mL of dioxane were added 1.25 mL of methyl iodide (20mmol) to give 104 mg of Compound N^(o) 3 as a yellow solid withoutpurification.

Melting point=200-203° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.69-7.63 (m, 1H), 7.39-7.33 (m, 1H),7.33-7.21 (m, 4H), 7.12-7.04 (m, 2H), 6.04 (d, J=5.2 Hz, 1H), 3.67-3.46(m, 2H), 3.29 (s, 3H), 3.28-3.20 (m, 1H), 3.15 (d, J=18.7 Hz, 1H), 2.25(s, 3H), 2.14-1.96 (m, 2H), 1.48-1.18 (m, 2H), 0.9 (t, J=7.4 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.1, 135.3, 134.4, 130.29, 130.22,130.1 (2C), 129.2, 128.4, 124.5, 123.8, 120.6, 82.9, 71.6, 54.1, 46.5,31.7, 26.1, 20.4, 14.1, 13.8.

IR (neat) (cm⁻¹): λ_(max)=3467, 3008, 2960, 2932, 2873, 1612, 1479,1461, 1425, 1395, 1275, 1233, 1159, 1083, 1059, 1042, 917, 897, 810,786, 767, 677.

HRMS (ESI positive):

Calculated for C₂₁H₂₆N [M−I]⁺ 292.2065; Found 292.2061.

[α]_(D) ²⁰+151° (c 0.5, MeOH).

Compound N^(o) 4

Compound N^(o) 4 is prepared according to the general procedure D.

To a solution of 85 mg of(5S,10R)-12-isobutyl-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.3 mmol) in 1.5 mL of dioxane were added 1.5 mL of methyl iodide (24.1mmol) to give 100 mg of Compound N^(o) 4 as a white solid withoutpurification.

Yield=75%.

Melting point=216-217° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.70 (br d, J=6.9 Hz, 1H), 7.37-7.31(m, 1H), 7.31-7.20 (m, 4H), 7.11-7.02 (m, 2H), 6.22 (d, J=5.2 Hz, 1H),3.60 (dd, J=18.5 Hz, 5.4 Hz, 1H), 3.30 (s, 3H), 3.21 (d, J=18.5 Hz, 1H),3.16-3.07 (m, 2H), 2.63 (sept, J=6.3 Hz, 1H), 2.23 (s, 3H), 1.17 (d,J=6.6 Hz, 3H), 1.12 (d, J=6.6 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.4, 135.3, 134.8, 130.3, 130.25,130.1, 130.0, 129.0, 128.4, 124.6, 123.8, 120.6, 84.1, 72.0, 61.2, 46.6,32.0, 25.0, 23.7, 23.3, 14.2.

IR (neat) (cm⁻¹): λ_(max)=3462, 3011, 2966, 2931, 2875, 1613, 1479,1458, 1426, 1393, 1277, 1233, 1158, 1080, 1044, 971, 919, 908, 789, 717,679, 640.

HRMS (ESI positive):

Calculated for C₂₁H₂₆N [M−I]⁺ 292.2065; Found 292.2060.

[α]_(D) ²⁰+178° (c 0.54, MeOH).

Compound N^(o) 5

Compound N^(o) 5 is prepared according to the general procedure D.

To a solution of 70 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.25 mmol) in 1 mL of dioxane were added 1.25 mL of methyl iodide (20mmol) to give 113 mg of Compound N^(o) 5 as a white solid withoutpurification.

Yield=90%.

Melting point=103-105° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.62 (br d, J=6.7 Hz, 1H), 7.37-7.31(m, 1H), 7.31-7.21 (m, 4H), 7.10-7.03 (m, 2H), 6.12 (d, J=5.1 Hz, 1H),3.84-3.70 (m, 2H), 3.37 (s, 3H), 3.23-3.10 (m, 2H), 2.26 (s, 3H),1.51-1.38 (m, 1H), 0.94-0.83 (m, 1H), 0.80-0.69 (m, 2H), 0.51-0.42 (m,1H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.1, 135.3, 134.7, 130.4, 130.2,130.0 (2C), 129.3, 128.4, 124.2, 123.7, 120.6, 82.3, 72.2, 58.4, 46.1,31.8, 14.6, 7.8, 6.7, 3.9.

IR (neat) (cm⁻¹): λ_(max)=3462, 3077, 3000, 2939, 1613, 1478, 1460,1426, 1391, 1359, 1275, 1173, 1084, 1059, 1032, 991, 917, 840, 788, 767,717, 639.

HRMS (ESI positive):

Calculated for C₂₁H₂₄N [M−I]⁺ 290.1909; Found 290.1909.

[α]_(D) ²⁰+126° (c 0.54, MeOH).

Compound N^(o) 6

Compound N^(o) 6 is prepared according to the general procedure D.

To a solution of 50 mg of(5S,10R)-12-(cyclopentylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.16 mmol) in 1 mL of dioxane were added 0.8 mL of methyl iodide (13mmol) to give 56 mg of Compound N^(o) 6 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield=74%.

Melting point=125-127° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.68 (br d, J=6.8 Hz, 1H), 7.38-7.31(m, 1H), 7.31-7.21 (m, 4H), 7.12-7.04 (m, 2H), 6.23 (d, J=4.9 Hz, 1H),3.62 (dd, J=18.9 Hz, 5.4 Hz, 1H), 3.42-3.35 (m, 2H), 3.29 (s, 3H), 3.15(d, J=18.7 Hz, 1H), 2.79-2.65 (m, 1H), 2.24 (s, 3H), 2.10-1.98 (m, 1H),1.76-1.50 (m, 5H), 1.43-1.32 (m, 1H), 1.27-1.15 (m, 1H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.8, 135.4, 134.6, 130.3, 130.2,130.1, 130.0, 129.1, 128.4, 124.5, 123.7, 120.6, 83.3, 71.9, 59.5, 46.9,35.8, 33.8, 33.6, 31.8, 25.3, 24.9, 14.1.

IR (neat) (cm⁻¹): λ_(max)=3462, 3075, 3010, 2960, 2945, 2906, 2869,1612, 1478, 1459, 1426, 1395, 1359, 1275, 1175, 1081, 1059, 918, 787,726, 639.

HRMS (ESI positive):

Calculated for C₂₃H₂₈N [M−I]⁺ 318.2222; Found 318.2220.

[α]_(D) ²⁰+125° (c 0.51, MeOH).

Compound N^(o) 7

Compound N^(o) 7 is prepared according to the general procedure D.

To a solution of 85 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)acetimidicacid (0.31 mmol) in 1.5 mL of dioxane was added 1.5 mL of methyl iodide(24.1 mmol) to give 90 mg of Compound N^(o) 7 as a white solid withoutpurification.

Yield: 69%.

Melting point=189-192° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 8.49 (br s, 1H), 7.49-7.28 (m, 6H),7.20-7.14 (m, 1H), 7.13-7.06 (m, 1H), 6.35 (br s, 1H), 5.79 (d, J=5.0Hz, 1H), 5.48 (d, J=14.5 Hz, 1H), 3.97 (dd, J=18.7 Hz, 5.0 Hz, 1H), 3.8(d, J=14.5 Hz, 1H), 3.29 (s, 3H), 3.13 (d, J=18.7 Hz, 1H), 2.46 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 166.0, 141.9, 134.7, 134.1, 130.6,130.4 (2C), 130.3, 129.1, 128.7, 124.3, 123.6, 121.0, 84.8, 73.6, 54.8,45.9, 31.8, 14.6.

IR (neat) (cm⁻¹): λ_(max)=3314, 3146, 3013, 1689, 1606, 1477, 1458,1428, 1413, 1392, 1321, 1273, 1233, 1184, 1114, 1083, 1019, 983, 897,776, 731.

HRMS (ESI positive):

Calculated for C₁₉H₂₁N₂O [M−I]⁺ 293.1654; Found 293.1662.

[α]_(D) ²⁰+90° (c 0.52, MeOH).

Compound N^(o) 8

Compound N^(o) 8 is prepared according to the general procedure D.

To a solution of 165 mg of(5S,10R)-12-(4-fluorobenzyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 108 mg of Compound N^(o) 8 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 46%.

Melting point=92-94° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.61-7.51 (m, 3H), 7.50-7.31 (m, 5H),7.31-7.23 (m, 1H), 7.15-7.05 (m, 3H), 6.24 (d, J=5.6 Hz, 1H), 5.64 (d,J=13.4 Hz, 1H), 4.74 (d, J=13.4 Hz, 1H), 4.13 (dd, J=18.8 Hz, 5.7 Hz,1H), 3.34 (s, 3H), 3.26 (d, J=18.8 Hz, 1H), 2.00 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 165.7, 162.4, 143.3, 135.5, 135.4,135.0, 134.4, 130.9, 130.7, 130.2, 130.1, 129.6, 128.7, 124.2, 123.6,120.7, 116.8, 116.5, 82.4, 73.6, 57.3, 44.2, 32.3, 15.2.

IR (neat) (cm⁻¹): λ_(max)=3452, 3033, 2934, 1605, 1512, 1478, 1458,1424, 1392, 1302, 1230, 1163, 1082, 1016, 919, 907, 862, 833, 763, 717,641.

HRMS (ESI positive):

Calculated for C₂₄H₂₃NF [M−I]⁺ 344.1815; Found 344.1812.

[α]_(D) ²⁰+153° (c 0.49, MeOH).

Compound N^(o) 9

Compound N^(o) 9 is prepared according to the general procedure D.

To a solution of 190 mg of(5S,10R)-5-methyl-12-(3-(trifluoromethyl)benzyl)-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 75 mg of Compound N^(o) 9 as a pale yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 29%.

Melting point=167-170° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 8.04 (d, J=7.9 Hz, 1H), 7.75-7.68 (m,1H), 7.65-7.55 (m, 2H), 7.49-7.23 (m, 7H), 7.06 (d, J=7.4 Hz, 1H), 6.31(d, J=5.5 Hz, 1H), 5.81 (d, J=13.2 Hz, 1H), 4.8 (d, J=13.2 Hz, 1H), 4.14(dd, J=19.0 Hz, 5.5 Hz, 1H), 3.37 (s, 3H), 3.26 (d, J=19.0 Hz, 1H), 1.91(s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.1, 137.2, 134.9, 134.3, 131.0,130.9, 130.5, 130.4, 130.2 (2C), 129.7, 129.4, 128.8 (2C), 127.7, 123.6,123.5, 120.7 (2C), 82.6, 74.1, 57.7, 44.1, 32.2, 153.

IR (neat) (cm⁻¹): λ_(max)=3447, 3015, 2928, 1616, 1478, 1453, 1423,1393, 1329, 1274, 1209, 1182, 1168, 1125, 1018, 971, 919, 871, 808, 728,642.

HRMS (ESI positive):

Calculated for C₂₅H₂₃NF₃ [M−I]⁺ 394.1783; Found 394.1779.

[α]_(D) ²⁰+136° (c 0.50, MeOH).

Compound N^(o) 10

Compound N^(o) 10 is prepared according to the general procedure D.

To a solution of 90 mg of(5S,10R)-12-isopentyl-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.31 mmol) in 1 mL of dioxane were added 1.5 mL of methyl iodide (24.1mmol) to give 100 mg of Compound N^(o) 10 as a yellow solid withoutpurification.

Yield=74%.

Melting point=215-217° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.67 (br d, J=6.9 Hz, 1H), 7.41-7.35(m, 1H), 7.35-7.25 (m, 4H), 7.13-7.05 (m, 2H), 6.06 (d, J=5.0 Hz, 1H),3.67-3.44 (m, 3H), 3.29 (s, 3H), 3.16 (d, J=18.9 Hz, 1H), 2.26 (s, 3H),2.06-1.90 (m, 2H), 1.62 (sept, J=6.6 Hz, 1H), 0.9 (d, J=6.6 Hz, 3H),0.87 (d, J=6.6 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.0, 135.2, 134.4, 130.3, 130.2,130.1, 130.0, 129.2, 128.4, 124.5, 123.8, 120.7, 83.0, 71.5, 53.1, 46.5,32.4, 31.7, 26.7, 22.8, 22.3, 14.2.

IR (neat) (cm⁻¹): λ_(max)=3467, 3010, 2958, 2872, 1613, 1481, 1462,1425, 1393, 1273, 1234, 1160, 1084, 1045, 919, 785, 765, 729, 639.

HRMS (ESI positive):

Calculated for C₂₂H₂₈N [M−I]⁺ 306.2222; Found 306.2220.

[α]_(D) ²⁰+137° (c 0.54, MeOH).

Compound N^(o) 11

Compound N^(o) 11 is prepared according to the general procedure D.

To a solution of 66 mg of(5S,10R)-5-methyl-12-propyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.25 mmol) in 1.25 mL of dioxane was added 1.25 mL of methyl iodide(20.1 mmol) to give 44 mg of Compound N^(o) 11 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 42%.

Melting point=214-217° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.69 (br d, J=6.4 Hz, 1H), 7.42-7.27(m, 5H), 7.16-7.07 (m, 2H), 6.12 (d, J=4.7 Hz, 1H), 3.69-3.51 (m, 2H),3.34 (s, 3H), 3.25-3.10 (m, 2H), 2.27 (s, 3H), 2.23-2.07 (m, 2H), 0.99(t, J=7.4 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.1, 135.3, 134.5, 130.4, 130.2,130.1, 130.0, 129.2, 128.4, 124.5, 123.8, 120.6, 82.9, 71.6, 55.7, 46.6,31.7, 18.2, 14.0, 11.6.

IR (neat) (cm⁻¹): λ_(max)=3462, 3008, 2968, 2877, 1612, 1480, 1459,1425, 1395, 1275, 1261, 1233, 1104, 1081, 1041, 1018, 947, 880, 841,782, 766, 731, 697.

HRMS (ESI positive):

Calculated for C₂₀H₂₄N [M−I]⁺ 278.1909; Found 278.1908.

[α]_(D) ¹⁴+124° (c 0.17, MeOH).

Compound N^(o) 12

Compound N^(o) 12 is prepared according to the general procedure D.

To a solution of 82 mg of(5S,10R)-12-hexyl-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.26 mmol) in 1.5 mL of dioxane was added 1.3 mL of methyl iodide (21mmol) to give 43 mg of Compound N^(o) 12 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield=36%.

Melting point=200-203° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.69 (m, 1H), 7.42-7.27 (m, 5H),7.15-7.09 (m, 2H), 6.13 (d, J=5.0 Hz, 1H), 3.63 (dd, J=19.2 Hz, 5.0 Hz,1H), 3.57-3.48 (m, 1H), 3.35 (s, 3H), 3.33-3.26 (m, 1H), 3.18 (d, J=19.2Hz, 1H), 2.27 (s, 3H), 2.16-2.03 (m, 2H), 1.46-1.19 (m, 6H), 0.83 (t,J=6.3 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.0, 135.3, 134.5, 130.31, 130.25,130.1, 130.0, 129.2, 128.5, 124.5, 123.8, 120.6, 82.9, 71.6, 54.4, 46.5,31.7, 31.3, 26.8, 24.4, 22.6, 14.1, 13.8.

IR (neat) (cm⁻¹): λ_(max)=3462, 3075, 3010, 2956, 2927, 2871, 2856,1614, 1480, 1460, 1425, 1395, 1308, 1275, 1233, 1159, 1082, 920, 809,783, 748, 639.

HRMS (ESI positive):

Calculated for C₂₃H₃₀N [M−I]⁺ 320.2378; Found 320.2378.

[α]_(D) ¹⁴+150° (c 0.26, MeOH

Compound N^(o) 13

Compound N^(o) 13 is prepared according to the general procedure D.

To a solution of 100 mg of(5S,10R)-5-methyl-12-(2-methylbutyl)-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.34 mmol) in 1.5 mL of dioxane were added 1.5 mL of methyl iodide(24.1 mmol) to give 46 mg of Compound N^(o) 13 as a white solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield=31%.

Melting point=181-184° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.74 (br t, J=7.0 Hz, 1H), 7.44-7.29(m, 5H), 7.15-7.09 (m, 2H), 6.36 (d, J=5.3 Hz, 1H, dia 1), 6.31 (d,J=5.3 Hz, 1H, dia 2), 3.72 (dd, J=18.8 Hz, 5.3 Hz, 1H, dia 1), 3.67 (dd,J=18.8 Hz, 5.3 Hz, 1H, dia 2), 3.41-3.37 (m, 1H), 3.35 (s, 3H, dia 1),3.33 (s, 3H, dia 2), 3.32-3.15 (m, 3H), 2.53-2.35 (m, 1H), 2.29 (s, 3H,dia 1), 2.28 (s, 3H, dia 2), 1.66-1.53 (m, 1H), 1.27 (d, J=6.5 Hz, 3H,dia 1), 1.21 (d, J=6.5 Hz, 3H, dia 2), 0.97-0.87 (m, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.5 (dia 1), 142.3 (dia 2), 135.4(dia 1), 135.3 (dia 2), 134.9 (dia 1), 134.8 (dia 2), 130.3, 130.1,130.0, 129.1 (dia 1) 129.0 (dia 2), 128.5, 124.5, 123.8, 120.7, 120.6,84.0 (dia 1), 83.9 (dia 2), 72.3 (dia 1), 72.1 (dia 2), 61.1 (dia 1),60.1 (dia 2), 47.0 (dia 1), 46.1 (dia 2), 32.0 (dia 1), 31.9 (dia 2),30.8 (dia 1), 30.7 (dia 2), 30.3 (dia 1), 29.6 (dia 2), 20.7 (dia 1),19.7 (dia 2), 14.2, 11.4 (dia 1), 11.2 (dia 2).

IR (neat) (cm⁻¹): λ_(max)=3452, 3011, 2964, 2933, 2876, 1614, 1479,1460, 1425, 1395, 1341, 1307, 1274, 1250, 1233, 1191, 1158, 1081, 1045,1018, 970, 940, 918, 871, 788, 765, 728, 717, 677, 639.

HRMS (ESI positive):

Calculated for C₂₂H₂₈N [M−I]⁺ 306.2222; Found 306.2219.

[α]_(D) ²⁰+180° (c 0.44, MeOH).

Compound N^(o) 14

Compound N^(o) 14 is prepared according to the general procedure D.

To a solution of 84 mg of (+)-MK801 maleate (0.25 mmol) in 1 mL ofdioxane were added 324 mg of cesium carbonate (1 mmol) and 1.6 mL ofethyl iodide (20 mmol) to give 80 mg of Compound N^(o) 14 as a whitesolid without purification.

Yield: 79%.

Melting point=237-238° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.63 (d, J=6.8 Hz, 1H), 7.41-7.35 (m,1H), 7.33-7.21 (m, 4H), 7.12-7.04 (m, 2H), 6.07 (d, J=5.3 Hz, 1H), 3.9(dd, J=19.5 Hz, 5.4 Hz, 1H), 3.86-3.72 (m, 2H), 3.68-3.53 (m, 1H),3.38-3.24 (m, 1H), 3.14 (d, 19.5 Hz, 1H), 2.26 (s, 3H), 1.65 (td, J=7.2Hz, 2.2 Hz, 6H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.7, 135.5, 134.3, 130.4, 130.3,130.1, 130.0, 129.9, 128.2, 123.7, 123.6, 120.4, 83.8, 68.7, 52.1, 48.0,32.0, 15.5, 11.5, 11.2.

IR (neat) (cm⁻¹): λ_(max)=3467, 3019, 2981, 2829, 1613, 1484, 1460,1452, 1428, 1396, 1308, 1295, 1250, 1231, 1153, 1133, 1076, 1040, 918,903, 804, 787, 717, 641.

HRMS (ESI positive):

Calculated for C₂₀H₂₄N [M−I]⁺ 278.1909; Found 278.1919.

[α]_(D) ²⁰+200° (c 0.50, MeOH).

Compound N^(o) 15

Compound N^(o) 15 is prepared according to the general procedure D.

To a solution of 100 mg of(5S,10R)-12-(cyclohexylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.32 mmol) in 1.5 mL of dioxane was added 1.5 mL of methyl iodide (24.1mmol) to give 33 mg of Compound N^(o) 15 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield=18%.

Melting point=220-222° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.70 (d, J=7.0 Hz, 1H), 7.42-7.27 (m,5H), 7.15-7.07 (m, 2H), 6.33 (d, J=5.0 Hz, 1H), 3.67 (dd, J=19.1 Hz, 5.0Hz, 1H), 3.35 (s, 3H), 3.24-3.12 (m, 3H), 2.44-2.33 (m, 1H), 2.26 (s,3H), 2.05-1.92 (m, 2H), 1.80-1.41 (m, 4H), 1.30-0.97 (m, 4H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.5, 135.4, 134.9, 130.4, 130.3,130.2, 130.0, 129.2, 128.5, 124.5, 123.8, 120.7, 83.8, 72.3, 60.9, 46.8,34.0, 33.8, 33.5, 32.0, 26.0, 25.8, 25.0, 14.2.

IR (neat) (cm⁻¹): λ_(max)=3437, 3009, 2953, 1613, 1478, 1461, 1448,1425, 1396, 1357, 1275, 1183, 1018, 919, 788, 765, 728, 639.

HRMS (ESI positive):

Calculated for C₂₄H₃₀N [M−I]⁺ 332.2378; Found 332.2385.

[α]_(D) ²⁰+126° (c 0.27, MeOH).

Compound N^(o) 16

Compound N^(o) 16 is prepared according to the general procedure D.

To a solution of 60 mg of(5S,10R)-12-benzyl-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.19 mmol) in 1 mL of dioxane was added 0.8 mL of methyl iodide (13mmol) to give 24 mg of Compound N^(o) 16 as a white solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 28%.

Melting point=220-222° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.57 (d, J=7.2 Hz, 1H), 7.50-7.29 (m,10H), 7.29-7.22 (m, 1H), 7.05 (d, J=7.4 Hz, 1H), 6.28 (d, J=5.5 Hz, 1H),5.61 (d, J=13.2 Hz, 1H), 4.71 (d, J=13.2 Hz, 1H), 4.14 (dd, J=18.8 Hz,5.9 Hz, 1H), 3.33 (s, 3H), 3.23 (d, J=18.8 Hz, 1H), 1.96 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.5, 135.2, 134.6, 133.4 (2C), 130.9(2C), 130.6, 130.2, 130.1, 129.8, 129.4 (2C), 128.6, 128.3, 123.7,123.6, 120.6, 82.2, 73.8, 58.5, 44.1, 32.2, 15.1.

IR (neat) (cm⁻¹): λ_(max)=3457, 3067, 3008, 2959, 2921, 2851, 1605,1584, 1498, 1458, 1422, 1393, 1303, 1273, 1250, 1180, 1134, 1078, 1049,1033, 970, 919, 907, 761, 732 704, 639.

HRMS (ESI positive):

Calculated for C₂₄H₂₄N [M−I]⁺ 326.1909; Found 326.1908.

[α]_(D) ¹⁵+93° (c 0.05, MeOH).

Compound N^(o) 17

Compound N^(o) 17 is prepared according to the general procedure D.

To a solution of 80 mg of(5S,10R)-12-(cyclobutylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.28 mmol) in 1.5 mL of dioxane were added 1.4 mL of methyl iodide(22.5 mmol) to give 31 mg of Compound N^(o) 17 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield=25%.

Melting point=159-162° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.7 (br d, J=6.9 Hz, 1H), 7.40-7.27 (m,5H), 7.15-7.05 (m, 2H), 6.36 (d, J=5.2 Hz, 1H), 3.64 (dd, J=18.6 Hz, 5.2Hz, 1H), 3.48-3.41 (m, 2H), 3.22 (s, 3H), 3.16 (d, J=18.6 Hz, 1H),2.51-2.41 (m, 1H), 2.25 (s, 3H), 2.11-2.00 (m, 2H), 1.91-1.77 (m, 2H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.8, 135.3, 134.5, 130.4, 130.2,130.1, 130.0, 129.2, 128.4, 124.5, 123.7, 120.6, 82.6, 71.8, 58.9, 46.2,31.7, 31.0, 30.6, 27.3, 18.8, 14.1.

IR (neat) (cm⁻¹): λ_(max)=3430, 3075, 2960, 2933, 2906, 1613, 1478,1459, 1426, 1394, 1341, 1256, 1234, 1159, 1076, 1058, 1041, 1017, 971,918, 909, 840, 764, 727, 639.

HRMS (ESI positive):

Calculated for C₂₂H₂₆N [M−I]⁺ 304.2041; Found 304.045.

[α]_(D) ²⁰+121° (c 0.29, MeOH).

Compound N^(o) 18

Compound N^(o) 18 is prepared according to the general procedure D.

To a solution of 140 mg of(5S,10R)-5-methyl-12-((1-phenylcyclopropyl)methyl)-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.36 mmol) in 2 mL of dioxane were added 1.8 mL of methyl iodide (28.9mmol) to give 80 mg of Compound N^(o) 18 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 45%.

Melting point=174-176° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.48-7.26 (m, 9H), 7.25-7.20 (m, 2H),7.04-6.93 (m, 2H), 4.99 (d, J=5.4 Hz, 1H), 4.25 (d, J=14.2 Hz, 1H), 3.58(d, J=14.2 Hz, 1H), 3.31 (s, 3H), 3.24 (dd, J=18.9 Hz, 5.4 Hz, 1H), 2.65(d, J=18.9 Hz, 1H), 2.10 (s, 3H), 1.71-1.61 (m, 1H), 1.43-1.33 (m, 1H),1.32-1.22 (m, 1H), 0.96-0.86 (m, 1H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.1, 141.9, 134.8, 134.7, 130.3,130.2 (2C), 130.1 (2C), 130.0, 129.6 (2C), 129.0, 128.6, 128.4, 124.1,123.3, 121.0, 83.9, 73.0, 62.7, 45.9, 31.6, 23.1, 15.5, 15.0, 14.9.

IR (neat) (cm⁻¹): λ_(max)=3450, 3005, 2959, 2921, 1605, 1495, 1478,1460, 1444, 1424, 1395, 1306, 1277, 1232, 1183, 1115, 1073, 1039, 990,919, 905, 836, 764, 725, 703, 675, 640.

HRMS (ESI positive):

Calculated for C₂₇H₂₈N [M−I]⁺ 366.2222; Found 366.2216.

[α]_(D) ¹⁵+116° (c 0.50, MeOH).

Compound N^(o) 19

Compound N^(o) 19 is prepared according to the general procedure D.

To a solution of 163 mg of(5S,10R)-5-methyl-12-(4-methylbenzyl)-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 97 mg of Compound N^(o) 19 as a pale yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 42%.

Melting point=134-136° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.55 (d, J=7.0 Hz, 1H), 7.47-7.27 (m,7H), 7.24-7.13 (m, 3H), 7.05 (d, J=7.3 Hz, 1H), 6.15 (d, J=5.2 Hz, 1H),5.39 (d, J=13.3 Hz, 1H), 4.64 (d, J=13.3 Hz, 1H), 4.11 (dd, J=19.1 Hz,5.8 Hz, 1H), 3.26 (s, 3H), 3.23 (d, J=19.1 Hz, 1H), 2.32 (s, 3H), 1.97(s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.5, 141.1, 135.2, 134.6, 133.1 (2C),130.8, 130.5, 130.11, 130.07 (2C), 130.0, 129.7, 128.5, 125.1, 123.6(2C), 120.6, 82.1, 73.6, 58.3, 44.2, 32.3, 21.5, 15.1.

IR (neat) (cm⁻¹): λ_(max)=3457, 3052, 3013, 2952, 2920, 1737, 1613,1478, 1457, 1422, 1393, 1326, 1272, 1206, 1176, 1083, 1051, 920, 907,887, 808, 787, 730, 638.

HRMS (ESI positive):

Calculated for C₂₅H₂₆N [M−I]⁺ 340.2065; Found 340.2072.

[α]_(D) ²⁰+124° (c 0.56, MeOH).

Compound N^(o) 20

Compound N^(o) 20 is prepared according to the general procedure D.

To a solution of 184 mg of(5S,10R)-12-(4-(tert-butyl)benzyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 83 mg of Compound N^(o) 20 as a pale yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 33%.

Melting point=152-154° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.56 (d, J=7.0 Hz, 1H), 7.49-7.35 (m,7H), 7.35-7.27 (m, 2H), 7.25-7.19 (m, 1H), 7.07 (d, J=7.0 Hz, 1H), 6.11(d, J=5.5 Hz, 1H), 5.39 (d, J=13.3 Hz, 1H), 4.67 (d, J=13.3 Hz, 1H),4.12 (dd, J=18.9 Hz, 5.5 Hz, 1H), 3.29 (s, 3H), 3.24 (d, J=18.9 Hz, 1H),2.01 (s, 3H), 1.27 (s, 9H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 154.2, 143.5, 135.2, 134.5, 132.9 (2C),130.7, 130.5, 130.1, 130.0, 129.7, 128.5, 126.4 (2C), 125.1, 123.7,123.6, 120.7, 82.2, 73.5, 58.1, 44.4, 35.0, 32.3, 31.3 (3C), 15.2.

IR (neat) (cm⁻¹): λ_(max)=3452, 3014, 2965, 2905, 2868, 1813, 1613,1515, 1477, 1459, 1422, 1393, 1365, 1337, 1303, 1269, 1233, 1179, 1160,1133, 1111, 1082, 1051, 1018, 970, 919, 907, 888, 860, 840, 820, 790,772, 730, 718, 674, 639.

HRMS (ESI positive):

Calculated for C₂₈H₃₂N [M−I]⁺ 382.2535; Found 382.2542.

[α]_(D) ²⁰+115° (c 0.55, MeOH).

Compound N^(o) 21

Compound N^(o) 21 is prepared according to the general procedure D.

To a solution of 200 mg of(5S,10R)-12-(4-methoxybenzyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.6 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 95 mg of Compound N^(o) 21 as a pale yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 39%.

Melting point=101-103° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.55 (d, J=7.0 Hz, 1H), 7.47-7.35 (m,5H), 7.35-7.27 (m, 2H), 7.24-7.19 (m, 1H), 7.05 (d, J=7.3 Hz, 1H), 6.88(d, J=8.7 Hz, 2H), 6.12 (d, J=5.4 Hz, 1H), 5.4 (d, J=13.5 Hz, 1H), 4.64(d, J=13.5 Hz, 1H), 4.1 (dd, J=18.9 Hz, 5.4 Hz, 1H), 3.79 (s, 3H), 3.26(s, 3H), 3.22 (d, J=18.9 Hz, 1H), 1.98 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 161.4, 143.5, 135.2, 134.7 (2C), 130.8,130.5, 130.1, 130.0, 129.7, 128.5, 123.6 (2C), 120.6, 119.9, 114.7 (2C),81.9, 73.4, 58.1, 55.6, 44.1, 32.2, 15.1.

IR (neat) (cm⁻¹): λ_(max)=3447, 3011, 2936, 2888, 1813, 1815, 1610,1582, 1515, 1478, 1459, 1421, 1392, 1337, 1282, 1257, 1182, 1111, 1083,1051, 919, 905, 887, 825, 787, 762, 731, 640.

HRMS (ESI positive):

Calculated for C₂₅H₂₆NO [M−I]⁺ 356.2014; Found 356.2021.

[α]_(D) ²⁰+115° (c 0.52, MeOH).

Compound N^(o) 22

Compound N^(o) 22 is prepared according to the general procedure D.

To a solution of 173 mg of(5S,10R)-12-(4-chlorobenzyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 70 mg of Compound N^(o) 22 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 29%.

Melting point=160-162° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.56 (d, J=7.1 Hz, 1H), 7.53-7.47 (m,2H), 7.47-7.27 (m, 7H), 7.26-7.21 (m, 1H), 7.07 (d, J=7.1 Hz, 1H), 6.17(d, J=5.3 Hz, 1H), 5.54 (d, J=13.3 Hz, 1H), 4.7 (d, J=13.3 Hz, 1H), 4.11(dd, J=19.2 Hz, 5.3 Hz, 1H), 3.29 (s, 3H), 3.25 (d, J=19.2 Hz, 1H), 2.01(s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.2, 137.2, 135.0, 134.7 (2C), 134.4,130.9, 130.7, 130.3, 130.1, 129.7 (2C), 129.6, 128.7, 126.8, 123.6 (2C),120.7, 82.5, 73.7, 57.3, 44.2, 32.3, 15.3.

IR (neat) (cm⁻¹): λ_(max)=3452, 3049, 3019, 2929, 1813, 1596, 1493,1477, 1455, 1424, 1392, 1338, 1297, 1248, 1181, 1084, 1050, 1015, 970,919, 907, 837, 814, 789, 723, 691, 671, 640.

HRMS (ESI positive):

Calculated for C₂₄H₂₃NCl [M−I]⁺ 360.1519; Found 360.1516.

[α]_(D) ²⁰+115° (c 0.50, MeOH).

Compound N^(o) 23

Compound N^(o) 23 is prepared according to the general procedure D.

To a solution of 173 mg of(5S,10R)-12-(2-chlorobenzyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 11 mg of Compound N^(o) 23 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 5%.

Melting point=129-131° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 8.10 (d, J=7.7 Hz, 1H), 7.7 (d, J=7.7Hz, 1H), 7.51-7.44 (m, 1H), 7.43-7.18 (m, 8H), 7.18-7.13 (m, 1H), 6.55(d, J=5.5 Hz, 1H), 5.13 (d, J=13.8 Hz, 1H), 4.73 (d, J=13.8 Hz, 1H),4.16 (dd, J=19.3 Hz, 5.5 Hz, 1H), 3.34 (d, J=19.3 Hz, 1H), 3.00 (s, 3H),3.25 (d, J=19.2 Hz, 1H), 2.07 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.6, 135.8, 135.2, 134.6, 134.4,132.3, 130.7, 130.6, 130.4, 130.1, 129.9, 129.3, 129.0, 128.2, 126.2,124.3, 124.0, 120.2, 83.1, 73.8, 53.9, 43.9, 32.5, 13.6.

IR (neat) (cm⁻¹): λ_(max)=3452, 3038, 2929, 1593, 1477, 1457, 1421,1391, 1271, 1233, 1206, 1161, 1134, 1057, 1041, 1018, 970, 918, 763,715, 682, 639.

HRMS (ESI positive):

Calculated for C₂₄H₂₃NCl [M−I]⁺ 360.1519; Found 360.1519.

[α]_(D) ²⁰+121° (c 0.55, MeOH).

Compound N^(o) 24

Compound N^(o) 24 is prepared according to the general procedure D.

To a solution of 163 mg of(5S,10R)-5-methyl-12-(2-methylbenzyl)-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.5 mmol) in 2.5 mL of dioxane was added 2.5 mL of methyl iodide (40.2mmol) to give 30 mg of Compound N^(o) 24 as a pale yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 14%.

Melting point=101-103° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.61 (d, J=7.1 Hz, 1H), 7.47-7.14 (m,10H), 7.02 (d, J=7.1 Hz, 1H), 6.66 (d, J=5.4 Hz, 1H), 5.51 (d, J=13.9Hz, 1H), 4.64 (d, J=13.9 Hz, 1H), 4.19 (dd, J=19.5 Hz, 5.4 Hz, 1H), 3.22(d, J=19.5 Hz, 1H), 3.12 (s, 3H), 2.34 (s, 3H), 1.91 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.4, 140.1, 135.2, 134.6, 134.0,132.2, 131.0 (2C), 130.6, 130.2, 130.0, 129.8, 128.5, 127.0, 126.9,124.0, 123.7, 120.4, 82.4, 74.5, 56.4, 43.9, 32.4, 21.3, 14.6.

IR (neat) (cm⁻¹): λ_(max)=3442, 3023, 2924, 1605, 1493, 1459, 1420,1391, 1272, 1255, 1232, 1161, 1082, 1047, 1018, 906, 882, 785, 768, 751,717, 640.

HRMS (ESI positive):

Calculated for C₂₅H₂₆N [M−I]⁺ 340.2065; Found 340.2059.

[α]_(D) ²⁰+92° (c 0.49, MeOH).

Compound N^(o) 25

Compound N^(o) 25 is prepared according to the general procedure D.

To a solution of 115 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.43 mmol) in 2 mL of dioxane was added 2 mL of methyl iodide (32.1mmol) to give 163 mg of Compound N^(o) 25 as a pale green solid withoutpurification.

Yield: 93%.

Melting point=216-219° C.

¹H NMR S (300 MHz, CDCl₃) (ppm): 7.51 (br d, J=7.2 Hz, 1H), 7.39-7.27(m, 5H), 7.15-7.08 (m, 2H), 5.89 (d, J=5.2 Hz, 1H), 4.57 (t, J=5.0 Hz,1H) 4.50-4.37 (m, 1H) 4.17 (dd, J=18.9 Hz, 5.4 Hz, 1H), 4.13-4.03 (m,1H), 3.66-3.48 (m, 2H), 3.39 (s, 3H), 3.04 (d, J=18.9 Hz, 1H), 2.24 (s,3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.1, 135.5, 135.0, 130.7, 130.3,130.1, 130.0, 129.5, 128.2, 123.8, 123.6, 120.7, 83.6, 73.5, 56.2, 55.0,46.1, 32.2, 13.7.

IR (neat) (cm⁻¹): λ_(max)=3313, 2969, 2871, 1610, 1478, 1458, 1393,1276, 1258, 1231, 1078, 1041, 1018, 957, 883, 763, 727, 720.

HRMS (ESI positive):

Calculated for C₁₉H₂₂NO [M−I]⁺ 280.1701; Found 280.1706.

[α]_(D) ¹⁴+188° (c 0.51, MeOH).

Compound N^(o) 26

Compound N^(o) 26 is prepared according to the general procedure D.

To a solution of 115 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.4 mmol) in 2 mL of dioxane were added 2.7 mL of ethyl iodide (33.8mmol) to give 134 mg of Compound N^(o) 26 as a pale green solid withoutpurification.

Yield: 80%.

Melting point=202-205° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.52 (d, J=6.7 Hz, 1H), 7.40-7.23 (m,5H), 7.15-7.07 (m, 2H), 5.79 (d, J=5.1 Hz, 1H), 4.50 (br s, 1H),4.25-3.96 (m, 4H), 369-3.62 (m, 2H), 3.45-3.34 (m, 1H), 3.06 (d, J=19.0Hz, 1H), 2.31 (s, 3H), 1.44 (t, J=7.1 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.1, 135.5, 134.9, 130.6, 130.2,130.1 (2C), 129.6, 128.2, 123.7, 123.2, 120.5, 85.0, 69.0, 56.5, 54.5,54.3, 32.2, 14.5, 11.9.

IR (neat) (cm⁻¹): λ_(max)=3314, 3013, 2921, 2820, 1612, 1478, 1461,1429, 1405, 1393, 1340, 1271, 1228, 1177, 1159, 1089, 1042, 1029, 975,926, 789, 766, 731, 696, 654, 631.

HRMS (ESI positive):

Calculated for C₂₀H₂₄NO [M−I]⁺ 294.1858; Found 294.1853.

[α]_(D) ²⁰+155° (c 0.49, MeOH).

Compound N^(o) 27

Compound N^(o) 27 is prepared according to the general procedure D.

To a solution of 110 mg of2-(5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.4 mmol) in 2 mL of dioxane were added 2.7 mL of ethyl iodide (33.8mmol) to give 71 mg of Compound N^(o) 27 after purification overpreparative plate (eluent: 90% DCM/10% MeOH).

Yield: 42%.

Melting point=205-208° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.51 (br d, J=6.7 Hz, 1H), 7.40-7.28(m, 5H), 7.18-7.07 (m, 2H), 5.82 (d, J=5.1 Hz, 1H), 4.63 (br s, 1H),4.28-3.93 (m, 4H), 3.74-3.44 (m, 3H), 3.07 (d, J=19.0 Hz, 1H), 2.29 (s,3H), 1.46 (t, J=7.1 Hz, 3H).

¹³C NMR δ (75 MHz, MeOD) (ppm): 145.0, 137.5, 136.1, 131.3, 131.1 (2C),131.0, 129.2, 125.3, 124.3, 121.9, 86.5, 71.7, 69.9, 57.6, 55.9, 55.0,32.6, 13.7, 11.4.

IR (neat) (cm⁻¹): λ_(max)=3279, 2916, 2886, 1614, 1476, 1455, 1424,1405, 1380, 1339, 1314, 1271, 1224, 1169, 1090, 1028, 1011, 973, 949,927, 898, 857, 789, 768, 753, 734, 717, 693, 652, 627.

HRMS (ESI positive):

Calculated for C₂₀H₂₄NO [M−I]⁺ 294.1858; Found 294.1854.

[α]_(D) ²⁰ 0° (c 0.60, MeOH).

Compound N^(o) 28

Compound N^(o) 28 is prepared according to the general procedure D.

To a solution of 98 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)acetonitrile(0.38 mmol) in 2 mL of dioxane was added 2 mL of methyl iodide (32.1mmol) to give 126 mg of Compound N^(o) 28 as a beige solid withoutpurification.

Yield: 82%.

Melting point=147-149° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.59 (br d, J=7.0 Hz, 1H), 7.50-7.33(m, 5H), 7.24-7.14 (m, 2H), 6.45 (d, J=5.2 Hz, 1H), 6.23 (d, J=16.6 Hz,1H), 4.91 (d, J=16.6 Hz, 1H), 4.0 (dd, J=19.2 Hz, 1H), 3.65 (s, 3H),3.23 (d, J=19.2 Hz, 1H), 2.44 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 141.6, 133.8, 133.0, 131.2, 131.0,130.7, 130.5, 129.0, 128.1, 124.1, 123.9, 120.7, 111.4, 84.9, 74.8,46.2, 43.7, 31.4, 14.7.

IR (neat) (cm⁻¹): λ_(max)=3450, 2890, 2810, 1611, 1478, 1460, 1394,1341, 1276, 1255, 1235, 1115, 1083, 1056, 1019, 988, 962, 918, 905, 886,839, 784, 765, 718, 677, 640.

HRMS (ESI positive):

Calculated for C₁₉H₁₉N₂[M−I]⁺ 275.1548; Found 275.1547.

[α]_(D) ²⁰+129° (c 0.54, MeOH).

Compound N^(o) 29

Compound N^(o) 29 is prepared according to the general procedure D.

To a solution of 92 mg ofN-(2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethyl)acetamide(0.3 mmol) in 1.5 mL of dioxane was added 1.5 mL of methyl iodide (24.1mmol) to give 90 mg of Compound N^(o) 29 as a yellow solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 28%.

Melting point=216-218° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 8.03 (t, J=5.2 Hz, 1H), 7.56 (br d,J=6.9 Hz, 1H), 7.40-7.27 (m, 5H), 7.17-7.08 (m, 2H), 5.88 (d, J=4.8 Hz,1H), 4.03 (dd, J=18.8 Hz, 5.2 Hz, 1H) 3.92 (q, J=5.7 Hz, 2H), 3.83-3.70(m, 1H), 3.52-3.40 (m, 1H), 3.36 (s, 3H), 3.09 (d, J=18.8 Hz, 1H), 2.21(s, 3H), 2.03 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 172.1, 142.3, 134.6, 134.5, 130.8,130.5, 130.3 (2C), 128.9, 128.4, 124.0, 123.5, 120.8, 84.0, 72.0, 52.4,46.5, 34.9, 31.7, 23.4, 13.3.

IR (neat) (cm⁻¹): λ_(max)=3250, 3043, 2939, 1666, 1479, 1461, 1442,1392, 1370, 1276, 1020, 905, 784, 764, 716, 644.

HRMS (ESI positive):

Calculated for C₂₁H₂₅N₂O [M−I]⁺ 321.1967; Found 321.1964.

[α]_(D) ²⁰+130° (c 0.20, MeOH).

Compound N^(o) 30

Compound N^(o) 30 is prepared according to the general procedure D.

To a solution of 343 mg of(5S,10R)-5-methyl-12-((1-phenylcyclopropyl)methyl)-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.89 mmol) in 3 mL of dioxane were added 4.6 mL of methyl iodide (73.9mmol) to give 260 mg of Compound N^(o) 30 as a beige solid afterpurification over preparative plate (eluent: 90% DCM/10% MeOH).

Yield: 55%.

Melting point=162-164° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.53-7.27 (m, 10H), 7.07-6.99 (m, 2H),5.25 (d, J=5.1 Hz, 1H), 4.38 (d, J=14.2 Hz, 1H), 3.66 (d, J=14.2 Hz,1H), 3.34 (s, 3H), 3.31 (dd, J=18.9 Hz, 5.0 Hz, 1H), 2.77 (d, J=18.9 Hz,1H), 2.14 (s, 3H), 1.71-1.61 (m, 1H), 1.51-1.41 (m, 1H), 1.32-1.22 (m,1H), 1.00-0.90 (m, 1H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.1, 140.7, 134.8, 134.7, 134.2,131.6 (2C), 130.4, 130.2, 130.11, 130.07, 129.8 (2C), 129.0, 128.5,124.0, 123.5, 120.9, 83.8, 73.1, 62.5, 45.9, 31.7, 22.6, 15.7, 15.4,15.1.

IR (neat) (cm⁻¹): λ_(max)=3423, 3013, 2959, 2851, 1605, 1494, 1479,1459, 1425, 1396, 1306, 1275, 1232, 1183, 1114, 1092, 1039, 1013, 991,919, 905, 832, 764, 718, 677, 640.

HRMS (ESI positive):

Calculated for C₂₇H₂₇NCl [M−I]⁺ 400.1832; Found 400.1826.

[α]_(D) ¹⁵+102° (c 0.50, MeOH).

Compound N^(o) 31

Compound N^(o) 31 is prepared according to the general procedure D.

To a solution of 170 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.62 mmol) in 3 mL of dioxane was added 4 mL of iodoethane (50 mmol) togive 55 mg of Compound N^(o) 31 as a white solid after purification overpreparative plate (eluent: 95% DCM/5% MeOH).

Yield=21%.

Melting point=189-191° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.62 (br d, J=7.0 Hz, 1H), 7.43-7.26(m, 5H), 7.14-7.07 (m, 2H), 6.06 (d, J=5.3 Hz, 1H), 4.14 (dd, J=14.1 Hz,4.6 Hz, 1H), 4.07 (dd, J=14.1 Hz, 7.5 Hz, 1H), 3.99 (dd, J=19.4 Hz, 5.4Hz, 1H), 3.32-3.18 (m, 1H), 3.14 (d, J=19.4 Hz, 1H), 3.12-3.03 (m, 1H),2.38 (s, 3H), 1.58 (t, J=7.2 Hz, 3H), 1.31-1.20 (m, 1H), 0.86-0.69 (m,2H), 0.47-0.37 (m, 1H), 0.35-0.26 (m, 1H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.8, 135.5, 134.2, 130.5, 130.3,130.1, 130.0, 129.9, 128.2, 123.5 (2C), 120.4, 83.2, 68.0, 57.4, 51.8,31.9, 15.4, 11.0, 7.8, 6.9, 5.5.

IR (neat) (cm⁻¹): λ_(max)=3452, 2998, 2929, 1614, 1461, 1428, 1394,1340, 1295, 1272, 1250, 1230, 1157, 1113, 1077, 1058, 1030, 919, 840,788, 764, 718, 639.

HRMS (ESI positive):

Calculated for C₂₂H₂₆N [M−I]⁺ 304.2065; Found 304.2059.

[α]_(D) ²⁰+113° (c 0.51, MeOH).

Compound N^(o) 32

To a solution of 90 mg of Compound N^(o) 26 (0.22 mmol) in 5 mL ofmethanol was added amberlite IRA-400 chloride (440 mg) and the mixturewas stirred at room temperature for 2 h. After filtration, the solutionwas concentrated under vacuum to give 70 mg of Compound N^(o) 32 as apale pink solid without any purification.

Melting point=115-120° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.51 (br d, J=7.1 Hz, 1H), 7.40-7.27(m, 5H), 7.13 (d, J=7.1 Hz, 1H), 7.08 (br d, J=7.1 Hz, 1H), 5.93 (d,J=4.9 Hz, 1H), 4.26 (dd, J=19 Hz, 5.6 Hz, 2H), 4.11-4.01 (m, 1H),3.99-3.90 (m, 1H), 3.76-3.55 (m, 3H), 3.46-3.38 (m, 1H), 3.05 (d, J=19.0Hz, 1H), 2.26 (s, 3H), 1.46 (t, J=7.1 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.1, 135.6, 135.3, 130.6, 130.2,130.1, 130.0, 128.1, 123.5, 123.3, 120.3, 84.6, 70.8, 69.7, 56.6, 54.6,54.3, 32.2, 14.2, 11.8.

IR (neat) (cm⁻¹): λ_(max)=3378, 2918, 2851, 1648, 1479, 1462, 1430,1396, 1341, 1273, 1229, 1178, 1091, 1043, 928, 789, 751, 716, 653, 630.

HRMS (ESI positive):

Calculated for C₂₀H₂₄NO [M−I]⁺ 294.1858; Found 294.1847.

[α]_(D) ²⁰+177° (c 0.27, MeOH).

Compound N^(o) 33

To a solution of 7.1 g of Compound N^(o) 31 (16.4 mmol) in 220 mL ofmethanol were added of amberlite IRA-400 chloride (56 g) and the mixturewas stirred at room temperature for 2 h. After filtration, the solutionwas concentrated under vacuum to give 5.1 g of Compound N^(o) 33 as awhite solid without any purification.

Yield: 92%.

Melting point: 180-181° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.57 (d, J=6.8 Hz, 1H), 7.33 (dt,J=13.5, 7.9 Hz, 5H), 7.16-7.04 (m, 2H), 6.21 (d, J=5.4 Hz, 1H), 4.43(dd, J=14.4, 4.4 Hz, 1H), 4.05 (m, 2H), 3.30-3.05 (m, 3H), 2.37 (s, 3H),1.62 (t, J=7.2 Hz, 3H), 1.18-0.98 (m, 1H), 0.85-0.59 (m, 2H), 0.47-0.32(m, 1H), 0.24 (m, 1H).

IR (neat) (cm⁻¹): λ_(max)=3387, 3001, 1627, 1459, 1430, 1395, 1247,1158, 1108, 1024, 758, 713, 634.

HRMS (ESI positive): Calculated for C₂₂H₂₆N [M−Cl]⁺ 304.2065; Found304.2061.

Compound N^(o) 34

Compound N^(o) 34 was prepared according to the procedure described forthe synthesis of Compound N^(o) 33. To a solution of 5.3 g of CompoundN^(o) 14 (13.1 mmol) in 177 mL of methanol were added amberlite IRA-400chloride (42.5 g) to give 5.1 g of Compound N^(o) 34 as a white solidwithout purification.

Yield: 93%.

Melting point=218-219° C.

¹H NMR S (300 MHz, CDCl₃) (ppm): 7.62 (d, J=7.0 Hz, 1H), 7.42-7.26 (m,5H), 7.13 (d, J=7.0 Hz, 1H), 7.08 (d, J=7.2 Hz, 1H), 6.24 (d, J=5.2 Hz,1H), 4.08 (m, 2H), 3.80 (m, 1H), 3.65 (m, 1H), 3.39 (m, 1H), 3.17 (d,J=19.5 Hz, 1H), 2.29 (s, 3H), 1.62-1.46 (m, 6H).

IR (neat) (cm⁻¹): λ_(max)=3347, 3016, 2972, 1455, 1405, 1237, 1044,1015, 762, 743.

HRMS (ESI positive): Calculated for C₂₀H₂₄N [M−Cl]⁺ 278.1909; Found278.1904.

Compound N^(o) 35

To a solution of 100 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.36 mmol) in 2 mL of acetonitrile in a microwave-type tube, were added2.81 mL of propyl iodide (28.8 mmol). The vial is sealed, and themixture was heated at 75° C. under stirring for 4 days. After beingallowed to cool to room temperature, the precipitate formed wasincreased by addition of pentane and filtered on sintered filter andwashed with ethyl acetate, then recovered by dissolution indichloromethane. The obtained solution was concentrated under reducedpressure 10 mbar) to give 137 mg of Compound N^(o) 35 as a yellow solidafter purification by silica-gel column chromatography (eluent 90%DCM/10% MeOH).

Yield: 85%.

Melting point=203-204° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.62 (d, J=6.1 Hz, 1H), 7.47-7.22 (m,5H), 7.12 (d, J=6.3 Hz, 2H), 6.08 (d, J=4.9 Hz, 1H), 4.07 (m, 1H), 3.79(t, J=12.6 Hz, 1H), 3.28-3.01 (m, 3H), 2.39 (s, 3H), 2.23 (m, 1H), 1.89(m, 1H), 1.24 (dd, J=9.6, 4.7 Hz, 2H), 0.93 (t, J=6.2 Hz, 3H), 0.79 (m,2H,), 0.40 (m, 2H).

IR (neat) (cm⁻¹): λ_(max)=3481, 3001, 1454, 1420, 1384, 1024, 926, 753.

HRMS (ESI positive): Calculated for C₂₃H₂₈N [M−I]⁺ 318.2222; Found318.2213.

Compound N^(o) 36

To a solution of 100 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.36 mmol) in 2 mL of acetonitrile in a microwave-type tube, were added2.81 mL of butyl iodide (28.8 mmol). The vial is sealed, and the mixturewas heated at 75° C. under stirring for 4 days. After being allowed tocool to room temperature, the precipitate formed was increased byaddition of pentane and filtered on sintered filter and washed withethyl acetate, then recovered by dissolution in dichloromethane. Theobtained solution was concentrated under reduced pressure Q0 mbar togive 131 mg of Compound N^(o) 36 as a yellow solid after purification bysilica-gel column chromatography (eluent 90% DCM/10% MeOH).

Yield: 79%.

Melting point=171-172° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.61 (d, J=7.2 Hz, 1H), 7.34 (dd,J=13.6, 5.3 Hz, 5H), 7.16-7.05 (m, 2H), 6.10 (d, J=4.7 Hz, 1H), 4.28(dd, J=14.3, 4.8 Hz, 1H), 4.09 (m, 1H), 3.81 (t, J=10.9 Hz, 1H), 3.14(m, 3H), 2.37 (s, 3H), 2.21 (m, 1H) 1.91 (s, 1H), 1.44-1.14 (m, 3H),0.93 (t, J=7.3 Hz, 3H), 0.78 (d, J=22.6 Hz, 2H), 0.51-0.41 (m, 1H),0.39-0.29 (m, 1H).

IR (neat) (cm⁻¹): λ_(max)=3441, 2962, 2932, 1726, 1449, 1424, 1237,1024, 758, 738.

HRMS (ESI positive): Calculated for C₂₄H₃₀N [M−I]⁺ 332.2378; Found332.2386.

Compound N^(o) 37

To a solution of 56 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.21 mmol) in 1.2 mL of acetonitrile in a microwave-type tube, wereadded 1.6 mL of propyl iodide (16.8 mmol). The vial is sealed, and themixture was heated at 90° C. under stirring for 4 days. After beingallowed to cool to room temperature, the precipitate formed wasincreased by addition of pentane and filtered on sintered filter andwashed with ethyl acetate, then recovered by dissolution indichloromethane. The obtained solution was concentrated under reducedpressure Q0 mbar) to give 55 mg of Compound N^(o) 37 as a yellow solidwithout purification.

Yield: 60%.

Melting point=221-222° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.50 (d, J=7.9 Hz, 1H), 7.35 (dd,J=19.9, 12.5 Hz, 5H), 7.12 (dd, J=13.1, 6.6 Hz, 2H), 5.82 (d, J=4.8 Hz,1H), 4.55 (t, J=5.4 Hz, 1H), 4.21 (m, 3H), 3.73 (t, J=12.4 Hz, 2H), 3.58(d, J=15.1 Hz, 1H), 3.34 (s, 1H), 3.05 (d, J=19.1 Hz, 1H), 2.28 (s, 3H),2.12 (m, 1H), 1.70-1.60 (m, 1H), 0.92 (t, J=7.2 Hz, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.9, 135.3, 134.9, 130.6, 130.3,130.1, 130.0, 129.5, 128.1, 123.4, 123.1, 120.3, 84.8, 69.7, 60.2, 56.5,54.9, 32.3, 19.5, 14.3, 11.3.

IR (neat) (cm⁻¹): λ_(max)=3328, 2957, 2349, 1445, 1034, 748.

Compound N^(o) 38

To a solution of 63 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.23 mmol) in 1.3 mL of acetonitrile in a microwave-type tube, wereadded 2.0 mL of butyl iodide (18.4 mmol). The vial is sealed, and themixture was heated at 90° C. under stirring for 4 days. After beingallowed to cool to room temperature, the precipitate formed wasincreased by addition of pentane and filtered on sintered filter andwashed with ethyl acetate, then recovered by dissolution indichloromethane. The obtained solution was concentrated under reducedpressure (10 mbar) to give 47 mg of Compound N^(o) 38 as a yellow solidwithout purification.

Yield: 45%.

Melting point=196-197° C.

¹H NMR δ (300 MHz, Acetone) (ppm): 7.72 (d, J=6.7 Hz, 1H), 7.61 (d,J=9.0 Hz, 1H), 7.48-7.31 (m, 5H), 7.21 (s, 1H), 5.86 (d, J=5.2 Hz, 1H),5.01 (t, J=5.4 Hz, 1H), 4.28-4.01 (m, 3H), 3.83 (t, J=11.1 Hz, 1H), 3.68(m, 2H), 3.53-3.37 (m, 1H), 3.19 (d, J=19.0 Hz, 1H), 2.46 (s, 3H), 2.14(m, 1H), 1.67 (m, 1H), 1.47-1.21 (m, 2H), 0.89 (t, J=7.3 Hz, 3H).

¹³C NMR δ (75 MHz, Acetone) (ppm): 145.0, 144.5, 137.1, 136.0, 131.0,130.8, 130.5 (2C), 128.5, 124.9, 124.2, 121.5, 80.7, 7.7, 58.7, 57.0,55.8, 32.4, 27.9, 20.5, 13.8, 13.5.

IR (neat) (cm⁻¹): λ_(max)=3304, 2962, 1440, 1034, 736.

Compound N^(o) 39

Compound N^(o) 39 is prepared according to the general procedure D.

To a solution of 44 mg of4-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)butan-1-ol(0.14 mmol) in 0.83 mL of dioxane were added 0.88 mL of ethyl iodide(11.2 mmol) to give 34 mg of Compound N^(o) 39 as a white solid withoutpurification.

Yield: 53%.

Melting point=201-202° C.

¹H NMR (300 MHz, CDCl₃) (ppm): 7.59 (d, J=7.4 Hz, 1H), 7.43-7.29 (m,5H), 7.16 (d, J=6.6 Hz, 1H), 7.09 (d, J=6.9 Hz, 1H), 5.91 (d, J=4.9 Hz,1H), 3.97 (d, J=13.9 Hz, 2H), 3.68 (m, 4H), 3.37 (dd, J=14.3, 6.7 Hz,1H), 3.15 (d, J=18.2 Hz, 1H), 3.01 (m, 1H), 2.31 (s, 3H), 2.25 (m, 1H),2.12-1.99 (m, 1H), 1.54 (dd, J=15.6, 8.2 Hz, 5H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 144.05, 141.55, 135.51, 134.26, 130.46,130.35, 130.13, 130.04, 129.74, 128.29, 123.54, 120.33, 83.95, 68.58,60.33, 53.06, 52.86, 31.82, 29.66, 22.12, 15.08, 11.76.

IR (neat) (cm⁻¹): λ_(max)=3377, 2912, 1454, 1384, 1069, 1024, 1014,1000, 767, 748.

HRMS (ESI positive): Calculated for C₂₂H₂₈NO [M−I]⁺ 322.2171; Found322.2167.

Compound N^(o) 40

Compound N^(o) 40 is prepared according to the general procedure D.

To a solution of 150 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.54 mmol) in 3.2 mL of dioxane were added 0.21 mL of ethyl iodide(2.72 mmol) to give 38 mg of Compound N^(o) 40 as a yellow solid withoutpurification.

Yield: 16%.

Melting point=179-180° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.59 (d, J=6.9 Hz, 1H), 7.34 (td,J=14.7, 7.3 Hz, 5H), 7.10 (dd, J=15.7, 7.7 Hz, 2H), 6.48 (d, J=5.8 Hz,1H), 4.40 (d, J=5.5 Hz, 1H), 4.28 (d, J=14.4 Hz, 2H), 3.88 (dd, J=18.8,5.3 Hz, 1H), 3.37-3.21 (m, 1H), 3.05 (dd, J=26.7, 17.3 Hz, 2H), 2.37 (s,3H), 1.26 (t, J=7.1 Hz, 3H), 0.82 (td, J=8.4, 4.0 Hz, 1H), 0.77-0.68 (m,1H), 0.48-0.38 (m, 1H), 0.00 (dd, J=9.5, 4.3 Hz, 1H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.3, 139.7, 135.1, 130.5, 130.4,130.3, 129.8, 128.2, 126.4, 123.8, 123.3, 120.2, 70.1, 59.1, 55.8, 55.4,49.2, 43.6, 31.6, 15.4, 7.8, 6.8, 5.9.

IR (neat) (cm⁻¹): λ_(max)=3328, 2998, 2995, 1459, 1424, 1019, 758.

HRMS (ESI positive): Calculated for C₂₂H₂₆NO [M−I]⁺ 320.2014; Found320.1992.

Compound N^(o) 41

To a solution of 110 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.39 mmol) in 2.2 mL of dioxane were added 2.7 mL of propargyl bromide(31.2 mmol). The vial is sealed, and the mixture was heated at 45° C.under stirring for 15 hours. After being allowed to cool to roomtemperature, the precipitate formed was increased by addition of pentaneand filtered on sintered filter and washed with ethyl acetate, thenrecovered by dissolution in dichloromethane. The obtained solution wasconcentrated under reduced pressure (10 mbar) to give 123 mg of CompoundN^(o) 41 as a white solid without purification.

Yield: 79%.

Melting point=168-169° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.70 (d, J=6.8 Hz, 1H), 7.37 (dd,J=16.6, 9.8 Hz, 5H), 7.12 (dd, J=11.6, 7.3 Hz, 2H), 6.62 (s, 1H), 4.81(s, 2H), 3.87 (dd, J=19.0, 5.2 Hz, 1H), 3.70 (dd, J=13.9, 4.6 Hz, 1H),3.50 (dd, J=13.8, 8.8 Hz, 1H), 3.24 (d, J=18.9 Hz, 1H), 2.92 (s, 1H),2.40 (s, 3H), 1.49 (m, 1H), 1.02-0.81 (m, 3H), 0.45 (d, J=5.6 Hz, 1H).

IR (neat) (cm⁻¹): λ_(max)=3310, 2986, 2361, 2181, 2045, 1460, 1047, 767,717.

HRMS (ESI positive): Calculated for C₂₃H₂₄N [M−Br]⁺ 314.1909; Found314.1909.

Compound N^(o) 42

To a solution of 146 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.55 mmol) in 2.9 mL of dioxane were added 3.9 mL of propargyl bromide(44.0 mmol). The vial is sealed, and the mixture was heated at 90° C.under stirring for 4 days. After being allowed to cool to roomtemperature, the precipitate formed was increased by addition of pentaneand filtered on sintered filter and washed with ethyl acetate, thenrecovered by dissolution in dichloromethane. The obtained solution wasconcentrated under reduced pressure 10 mbar to give 177 mg of CompoundN^(o) 42 as a white solid without purification.

Yield: 84%.

Melting point=201-202° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.61-7.50 (m, 1H), 7.35 (dt, J=17.2,8.3 Hz, 5H), 7.14 (d, J=6.4 Hz, 2H), 6.43 (d, J=5.1 Hz, 1H), 5.69-5.59(m, 1H), 5.52 (dd, J=17.4, 2.4 Hz, 1H), 4.75-4.59 (m, 1H), 4.37 (dd,J=19.1, 5.4 Hz, 1H), 4.24 (d, J=17.9 Hz, 1H), 3.98 (d, J=14.4 Hz, 1H),3.64 (t, J=13.7 Hz, 2H), 3.06 (d, J=18.8 Hz, 1H), 2.96 (d, J=2.3 Hz,1H), 2.35 (s, 3H).

IR (neat) (cm⁻¹): λ_(max)=3169, 2962, 2117, 1445, 1400, 1346, 1089,1094, 945, 846, 782, 767, 688.

Compound N^(o) 43

To a solution of 100 mg of(5S,10R)-12-(cyclopropylmethyl)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulene(0.36 mmol) in 2 mL of acetonitrile were added 1.2 mL of allyl bromide(14.4 mmol). The vial is sealed, and the mixture was heated at 50° C.under stirring for 15 hours. After being allowed to cool to roomtemperature, the precipitate formed was increased by addition of pentaneand filtered on sintered filter and washed with ethyl acetate, thenrecovered by dissolution in dichloromethane. The obtained solution wasconcentrated under reduced pressure (10 mbar) to give 97 mg of CompoundN^(o) 43 as a white solid without purification.

Yield: 68%.

Melting point=131-132° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.48 (dd, J=5.8, 2.5 Hz, 1H), 7.43-7.38(m, 1H), 7.36-7.25 (m, 4H), 7.17-7.08 (m, 2H), 6.47-6.26 (m, 1H), 5.91(d, J=5.0 Hz, 1H), 5.54 (d, J=10.1 Hz, 1H), 5.21 (d, J=16.7 Hz, 1H),4.75 (dd, J=13.4, 5.3 Hz, 1H), 4.19-4.10 (m, 1H), 3.97 (dd, J=19.0, 5.4Hz, 1H), 3.71 (dd, J=13.5, 8.8 Hz, 1H), 3.29 (dd, J=14.1, 8.8 Hz, 1H),3.13 (d, J=19.2 Hz, 1H), 2.41 (s, 3H), 1.32-1.18 (m, 1H), 0.85-0.69 (m,2H), 0.45 (d, J=3.2 Hz, 2H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 143.6, 135.4, 134.3, 130.3, 130.1,130.0, 129.9, 128.1, 127.1, 126.2, 123.4, 123.3, 120.4, 82.9, 69.0,59.2, 57.8, 31.8, 15.1, 7.9, 6.7, 5.4.

IR (neat) (cm⁻¹): λ_(max)=3495, 3005, 1731, 1621, 1461, 1448, 1393,1248, 1082, 994, 790, 768.

Compound N^(o) 44

To a solution of 50 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.18 mmol) in 1 mL of acetonitrile were added 0.65 mL of allyl bromide(7.2 mmol). The vial is sealed, and the mixture was heated at 90° C.under stirring for 4 days. After being allowed to cool to roomtemperature, the precipitate formed was increased by addition of pentaneand filtered on sintered filter and washed with ethyl acetate, thenrecovered by dissolution in dichloromethane. The obtained solution wasconcentrated under reduced pressure (10 mbar) to give 61 mg of CompoundN^(o) 44 as a white solid without purification.

Yield: 87%.

Melting point=196-197° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.34 (m, 6H), 7.17-7.07 (m, 2H), 6.20(dt, J=15.2, 9.7 Hz, 1H), 5.81 (d, J=5.1 Hz, 1H), 5.45 (dd, J=13.5, 7.7Hz, 2H), 5.23 (d, J=16.6 Hz, 1H), 4.65 (dd, J=14.0, 4.5 Hz, 1H), 4.35(dd, J=12.6, 6.6 Hz, 1H), 4.22 (dd, J=19.0, 5.6 Hz, 1H), 4.14-3.99 (m,2H), 3.67 (s, 2H), 3.04 (d, J=18.7 Hz, 1H), 2.32 (s, 3H).

IR (neat) (cm⁻¹): λ_(max)=3246, 1461, 1434, 1082, 1434, 1082, 924, 766,751.

Compound N^(o) 45

To a solution at 0° C. of 65 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethan-1-ol(0.24 mmol) in 1 mL of tetrahydrofuran were added 6 mg of sodium hydride(0.26 mmol). The solution was stirred for 30 min and 57 μL of methyliodide were added. The mixture was stirred at room temperature for 17hours and then diluted in diethyl ether. The organic was washed withwater and a saturated solution of sodium chloride. The organic layer wasdried over magnesium sulfate and concentrated under reduced pressure (10mbar) to give Compound N^(o) 45 as a white solid after purification bysilica-gel column chromatography (eluent 90% DCM/10% MeOH).

Yield: 28%.

Melting point=162-163° C.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.54-7.48 (m, 1H), 7.41-7.28 (m, 5H),7.11 (dd, J=12.9, 7.0 Hz, 2H), 5.61 (d, J=5.3 Hz, 1H), 4.27-4.08 (m,2H), 3.98-3.85 (m, 2H), 3.56 (dd, J=18.6, 8.2 Hz, 2H), 3.48 (s, 1H),3.38 (s, 3H), 3.05 (d, J=18.9 Hz, 1H), 2.33 (s, 3H).

¹³C NMR δ (75 MHz, CDCl₃) (ppm): 142.26, 135.0 (2C), 130.3, 130.2,130.1, 130.0, 129.0, 128.3, 123.8, 123.5, 120.9, 83.7, 74.1, 67.2, 59.7,53.0, 45.6, 32.0, 14.1.

IR (neat) (cm⁻¹): λ_(max)=3491, 2927, 1474, 1449, 1425, 1395, 1257,1202, 1108, 1024, 950, 767, 743, 713.

HRMS (ESI positive): Calculated for C₂₀H₂₄NO [M−I]⁺ 294.1858; Found294.1852.

Compound N^(o) 46

To a solution of 900 mg of (+)-MK801 maleate (2.67 mmol) in 30 mL ofacetonitrile were added 1.10 g of potassium carbonate (8.00 mmol) and0.70 mL of allyl bromide (8.00 mmol). The resulting mixture was refluxedfor 6 hours, allowed to cool down at room temperature and filtratedusing dichloromethane as solvent. After evaporation, the crude productwas purified by silica gel chromatography (dichloromethane/methanol:97.5/2.5 to 95/5) to give 122 mg of Compound N^(o) 46 as a white brownsolid.

Yield: 12%.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.53-7.50 (m, 1H), 7.42-7.28 (m, 5H),7.13-7.11 (m, 2H), 6.35-6.11 (m, 2H), 5.95 (d, J=4.9 Hz, 1H), 5.65-5.55(m, 3H), 5.27 (d, J=16.7 Hz, 1H), 4.67 (dd, J=14.2, 6.3 Hz, 1H), 4.53(dd, J=13.5, 5.4 Hz, 1H), 4.36 (dd, J=14.2, 7.9 Hz, 1H), 4.06 (dd,J=19.3, 5.1 Hz, 1H), 3.73 (dd, J=13.4, 8.7 Hz, 1H), 3.17 (d, J=19.2 Hz,1H), 2.35 (s, 3H).

MS (ESI positive): 302 [C₂₂H₂₄N]⁺

Compound N^(o) 47

Compound N^(o) 47 was prepared according to the procedure described forthe synthesis of Compound N^(o) 33. To a solution of 122 mg of CompoundN^(o) 46 (0.32 mmol) in 14 mL of methanol were added amberlite IRA-400chloride (1.02 g) to give 100 mg of Compound N^(o) 47 as a white brownsolid without purification.

Yield: 92%.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.49-7.46 (m, I H), 7.39-7.25 (m, 5H),7.14-7.07 (m, 2H), 6.40-6.26 (m, 1H), 6.19-6.06 (m, 1H), 5.99 (d, J=5.0Hz, 1H), 5.63-5.54 (m, 3H), 5.24 (d, J=16.9, 1H), 4.92 (dd, J=14.1, 6.4,1H), 4.53 (dd, J=5.4, 13.3 Hz, 1H), 4.39 (dd, J=14.2, 7.9 Hz, 1H), 4.11(dd, J=5.4, 19.1 Hz, 1H), 3.73 (dd, J=13.5, 8.8 Hz, 1H), 3.14 (d, J=19.3Hz, 1H), 2.32 (s, 3H).

Compound N^(o) 48

To a solution of 400 mg of2-((5S,10R)-5-methyl-10,11-dihydro-5H-5,10-epiminodibenzo[a,d][7]annulen-12-yl)ethanol(1.50 mmol) in 7.5 mL of dioxane were added 1.30 g of potassiumcarbonate (15.0 mmol) and 1.20 mL of 2-iodoethanol (15.3 mmol). Theresulting mixture was stirred and heated in a sealed tube at 100° C. for96 hours, allowed to cool down at room temperature and filtrated usingdichloromethane as solvent. After evaporation, the crude product waspurified by silica gel chromatography (dichloromethane/methanol:97.5/2.5 to 95/5) to give 300 mg of Compound N^(o) 48 as a white solid.

Yield: 46%.

¹H NMR δ (300 MHz, CDCl₃) (ppm): 7.57-7.55 (m, 1H), 7.40-7.26 (m, 5H),7.13-7.08 (m, 2H), 5.99 (d, J=4.9 Hz, 1H), 4.34-3.89 (m, 9H), 3.63-3.59(m, 1H), 3.43-3.37 (m, 1H), 3.08 (d, J=18.9 Hz, 1H), 2.32 (s, 3H).

The table 1 below illustrates Compounds N^(o) 1 to N^(o) 53 of theinvention:

TABLE 1

No Formula n R₁ R₂ Chirality Counterion X⁻  1

1 —H —CH₃ (+) I⁻  2

1 —CH₃ —CH₃ (+) I⁻  3

3 —CH₃ —CH₃ (+) I⁻  4

1 —CH(—CH₃)₂ —CH₃ (+) I⁻  5

1 -cyclopropyl —CH₃ (+) I⁻  6

1 -cyclopentyl —CH₃ (+) I⁻  7

1 —C(═NH)—OH —CH₃ (+) I⁻  8

1 -4-fluorophenyl —CH₃ (+) I⁻  9

1 -3-CF₃-phenyl —CH₃ (+) I⁻ 10

2 —CH(—CH₃)₂ —CH₃ (+) I⁻ 11

2 —CH₃ —CH₃ (+) I⁻ 12

5 —CH₃ —CH₃ (+) I⁻ 13

1 —CH(—CH₃)—CH₂—CH₃ —CH₃ (+) I⁻ 14

1 —CH₃ —CH₂—CH₃ (+) I⁻ 15

1 -cyclohexyl —CH₃ (+) I⁻ 16

1 -phenyl —CH₃ (+) I⁻ 17

1 -cyclobutyl —CH₃ (+) I⁻ 18

1 -cyclopropyl-phenyl —CH₃ (+) I⁻ 19

1 -4-CH₃-phenyl —CH₃ (+) I⁻ 20

1 -4-C(—CH₃)₃-phenyl —CH₃ (+) I⁻ 21

1 -4-OCH₃-phenyl —CH₃ (+) I⁻ 22

1 -4-chlorophenyl —CH₃ (+) I⁻ 23

1 -2-chlorophenyl —CH₃ (+) I⁻ 24

1 -2-CH₃-phenyl —CH₃ (+) I⁻ 25

2 —OH —CH₃ (+) I⁻ 26

2 —OH —CH₂—CH₃ (+) I⁻ 27

2 —OH —CH₂—CH₃ (±) I⁻ 28

1 —CN —CH₃ (+) I⁻ 29

2 —NH—CO—CH₃ —CH₃ (+) I⁻ 30

1 -cyclopropyl-4-chlorophenyl —CH₃ (+) I⁻ 31

1 -cyclopropyl —CH₂—CH₃ (+) I⁻ 32

2 —OH —CH₂—CH₃ (+) Cl⁻ 33

1 -cyclopropyl —CH₂—CH₃ (+) Cl⁻ 34

1 —CH₃ —CH₂—CH₃ (+) Cl⁻ 35

1 —cyclopropyl —(CH₂)₂—CH₃ (+) I⁻ 36

1 —cyclopropyl —(CH₂)₃—CH₃ (+) I⁻ 37

2 —OH —(CH₂)₂—CH₃ (+) I⁻ 38

2 —OH —(CH₂)₃—CH₃ (+) I⁻ 39

4 —OH —CH₂—CH₃ (+) I⁻ 40

1 -cyclopropyl —(CH₂)₂—OH (+) I⁻ 41

1 -cyclopropyl —CH₂—C≡CH (+) Br⁻ 42

2 —OH —CH₂—C≡CH (+) Br⁻ 43

1 -cyclopropyl —CH₂—CH═CH₂ (+) Br⁻ 44

2 —OH —CH₂—CH═CH₂ (+) Br⁻ 45

2 —O—CH₃ —CH₃ (+) I⁻ 46

1 —CH═CH₂ —CH₂—CH═CH₂ (+) Br⁻ 47

1 —CH═CH₂ —CH₂—CH═CH₂ (+) Cl⁻ 48

2 —OH —(CH₂)₂—OH (+) I⁻ 49

1 —CH₃ —CH(—CH₃)—CH₂—OH (+) Cl⁻ 50

2 —O—CH₃ —CH₂—CH₃ (+) Cl⁻ 51

2 —O—CH₂—CH₃ —CH₂—CH₃ (+) Cl⁻ 52

2 —F —CH₂—CH₃ (+) Cl⁻ 53

2 —N(CH₃)₂ —CH₂—CH₃ (+) Cl⁻

The table 2 below illustrates Compounds N^(o) 54 to N^(o) 56 of theinvention:

TABLE 2

R₅, R₆, Counterion No Formula n R₁ R₂ R₃ R₄ R₇ et R₈ R₉ R₁₀ Chirality X⁻54

1 —H —CH₃ —H —H —H —CH₃ —H (+) I⁻ 55

2 —CH₃ —CH₂—CH₃ —H —H —H —CH₃ —H (+) I⁻ 56

1 —H —CH₃ —H —O—CH₃ —H —H —H (+) I⁻

The compounds according to the invention were the subject ofpharmacological assays.

Example 2

Role of NMDA Receptors in the Development of Pulmonary Hypertension

To understand the functional importance of NMDARs in smooth musclecells, the Grin1 gene (encoding the obligatory GluN1 subunit) has beendeleted from the smooth muscle cells of mice. These knock out mice forNMDAR in PASMC were produced breeding mice expressing Cre recombinase insmooth muscle cells with floxed GRIN1 mice (GRIN1: gene coding for GluN1ubiquitous subunit of NMDARs).

Under chronic hypoxia (FiO₂ 10%, 3 weeks), KO mice develop an attenuatedform of PH compared to control mice, with a decreased right ventricularpressure and cardiac hypertrophy (Fulton index) (FIG. 1). In FIG. 1,P<0.01 and p<0.001 in KO mice compared to wild type under hypoxia, forright ventricular systolic pressure and Fulton index, respectively.

After chronic hypoxia (FiO₂ 10%, 3 weeks), KO mice also have a decreasedmuscularization of small vessels (diameter <50 μm) compared to controlmice (FIG. 2). Moreover, KO mice present less muscularized large vessels(75 μm<diameter <125 μm) in both normoxic and hypoxic conditionscompared to control mice (FIG. 2).

These results indicate that knocking out NMDAR in PASMC attenuatespulmonary vascular cell remodeling, cardiac remodeling and PH in hypoxicmice. Thus, PASMC NMDA receptors contribute to pulmonary vascular cellremodeling, cardiac remodeling and to pulmonary hypertension.

Example 3

In Vivo Brain Penetration Measurements

Compounds of the present invention provide a mean to prevent Blood-BrainBarrier. This assumption has been verified on rats.

Among methods addressing central nervous system penetration in drugdiscovery, in vivo equilibrium distribution between blood and brain inrodents is the most commonly used parameter to evaluate brainpenetration.

This parameter is defined as the ratio of concentrations in brain andblood, Kp_(“brain”) (C_(brain)/C_(plasma)) or log(BB). Log(BB) is thelogarithm of the ratio of the steady-state total concentration of acompound in the brain to that in the blood/plasma,log(BB)=log(C_(brain)/C_(plasma)). This parameter depends upon thepassive diffusion characteristics, the implication of membranetransporters at the BBB level and the relative drug binding affinitydifferences between the plasma proteins and brain tissue. Generally,compounds with a brain/plasma ratio of greater than 0.5 are consideredto have sufficient access to the CNS. Thus, compounds with a valuegreater than 1 freely cross the BBB.

Thus, the brain penetration of MK801, Compound N^(o) 1 and CompoundN^(o) 26 was measured in rat by establishing the brain/plasma ratio,Kp_(“brain”) in triplicate (3 rats/Compound). The enclosed FIG. 3 showsthe results on calculation of the Kp_(“brain”) for the three compoundsMK801, Compound N^(o) 1 and Compound N^(o) 26.

The Kp_(“brain”) value (defined as the total brain/plasma concentrationratio at steady state) was calculated in 3 rats for each compound MK801,Compound N^(o) 1 and

Compound N^(o) 26. Compounds N^(o) 1 and N^(o) 26 present a very lowKp_(“brain”) value as compared to MK801 (0.3±0.03 and 0.4±0.08 versus17.7±1.75).

In conclusion, as known and previously described, MK801 penetratesfreely across the BBB and intensively penetrate the CNS in rat. As weexpected, due to the presence of a quaternary ammonium and asdemonstrated by the Kp_(“brain”) values, the Compounds N^(o) 1 and N^(o)26 do not penetrate the CNS in rat.

Example 4

In Vitro Activity: Evaluation of NMDAR Blocking Activity UsingPatch-Clamp

Previous studies have shown that the NMDAR exists in the peripheralvasculature.

All NMDAR subunits were examined by RT-PCR and sequencing in theperipheral endothelium and peripheral vascular smooth muscle cells. Thesequences of these NMDAR subunits in both vascular cells showed a highsimilarity if not identity to the sequences of brain NMDAR (Chen H etal, J Vasc Surg 2005, Qureshi I et al Vasc Med 2005).

The molecules described herein were tested in serial concentrationsranging from 1 nM to 100 μM for their NMDAR blocking activity usingpatch-clamp.

Whole-cell voltage clamp recordings from rat hippocampal neurons werethen used to calculate IC₅₀ for each molecule. The IC₅₀ is theconcentration of an inhibitor where the response (or binding) is reducedby half NMDAR antagonist activity of selected compounds

Compound IC₅₀ (μM) Dizocilpine ((+)- 0.29 MK801 maleate) Compound No 10.65 Compound No 2 0.57 Compound No 3 0.50 Compound No 4 0.82 CompoundNo 5 0.40 Compound No 6 1.10 Compound No 26 0.4 Compound No 27 0.36Compound No 31 0.27

The results show that the parent molecule dizocilpine had an IC₅₀ of0.29 μM, which is consistent with its known antagonist activity.Compounds of the present invention have an activity ranging from 0.27 to1.10 μM. Of interest, results obtained with Compound N^(o) 31 (IC₅₀=0.27μM), Compound N^(o) 27 (IC₅₀=0.36 μM), and Compounds N^(o) 5 and N^(o)26 (IC₅₀=0.4 μM) clearly demonstrate that structural modification on thenitrogen atom of dizocilpine is not deleterious for activity.

1: Compound of formula (I):

wherein: R₁ represents a cyclobutyl group; R₂ represents a (C₁-C₁₀)alkylgroup; n is 1; R₃, R₄, R₅, R₆, R₇, R₈, R₉ and R₁₀ represent a hydrogenatom; and X⁻ is an anionic counterion selected from the group consistingof I⁻, Cl⁻, Br⁻, and OH⁻. 2: Compound according to claim 1, wherein R₂represents a methyl group or an ethyl group. 3: Compound according toclaim 1, wherein R₂ represents a methyl group. 4: Compound according toclaim 1, wherein R₂ represents an ethyl group. 5: Compound according toclaim 1, wherein the anionic counterion X⁻ is selected from the groupconsisting of I⁻ and Cl⁻. 6: Compound according to claim 1, wherein theanionic counterion X⁻ is I⁻. 7: Compound according to claim 1, whereinthe anionic counterion X⁻ is Cl⁻. 8: Compound according to claim 1,wherein the anionic counterion X⁻ is Br⁻. 9: Compound according to claim1, wherein the anionic counterion X⁻ is OH⁻. 10: Compound according toclaim 1, chosen from:

11: A pharmaceutical composition comprising at least one compoundaccording to claim 1, and at least one pharmaceutically acceptableexcipient. 12: A method for treating a disease or condition in a subjectcomprising administering to the subject a compound according to claim 1,wherein the disease or the condition is pulmonary hypertension. 13: Amethod for treating a disease or condition in a subject comprisingadministering to the subject a compound according to the claim 1,wherein the disease or the condition is selected from the groupconsisting of pulmonary arterial hypertension and thromboembolicpulmonary hypertension. 14: A method for treating a disease in a subjectcomprising administering to the subject a compound according to claim 1,wherein the disease is pulmonary arterial hypertension.